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Profntor if Bitltgy in Haiurftrd Ctlltgt and Inilrucltr in Ctmparatiiii 

Anattmj in ihi Marint Biilegical Lattrallrj at Cold 

Spring Harbtr. Lang liland 



A. C. McCLURG & CO. 



A. C. McGlurg & Co. 


Published September, 1916 

Copyrighted in Great Britain 



fttsQolf Leuckatt 



This manual has been written to supply the need which has been felt 
in this country for a long time of a book containing descriptions of the 
common invertebrate animals, by means of which their names and affinities 
can be determined. Excellent general manuals with analytical keys for 
the identification of the common insects already exist, but a person wishing 
to identify animals belonging to most of the other invertebrate groups 
must usually have recourse to technical papers and treatises which are 
for the most part inaccessible except to specialists. The book is intended 
more particularly for use in the eastern and central portions of the United 
States and Canada, and the endeavor has been made to include in it most 
of the common invertebrates except insects occurring in this region. In 
addition to these, representative species occurring in the western states and 
on the Pacific slope are included, as are also other species to which some 
special interest attaches and which are found in other parts of the world. 
Animals which inhabit the deep sea have not been included except in special 
cases where they are representative of their particular groups. 

The general plan of the book is similar to that of Leunis' Zoologie, 
a standard German work which has for two generations supplied the need 
of a general synopsis of animals in Europe, and has been extensively 
used elsewhere throughout the world. As in that work, the analytical 
tables and descriptions of species of each of the larger groups of animals 
are preceded by a morphological description of the group together with 
some account of the habits and distribution of the animals. In these 
descriptions all the technical terms appearing in the tables are explained. 
References to the principal authorities upon which the descriptions are 
based are given in footnotes, as are also references to important treatises 
and monographs which have appeared on the animals described. 

A knowledge of the historical basis of zoological names adds greatly 
to their significance and the author has consequently given la history 
of the nomenclature of each of the larger subdivisions of the animal 
kingdom in connection with the morphological description of it. A history 
of the general development of the system of classification since the pub- 
lication of the tenth edition of Ldnnffius' Systema Naturae land a brief 
survey of the progress of zoological studies in America are added in the 


An important object aimed at in these historical notes is to give the 
student of American animals a background for his knowledge of zoological 
names. In order to attain this object still more fully, brief biographical 
notices of the authors of these names, in so far as they appear in this work, 
have been introduced at the end of the book. 

In the choice of the scientific names of the animals described the author 
has endeavored to follow the best usage. He has usually conformed to 
the laws of priority established by the International Commission of Nomen- 
clature, and has adopted the rulings of the Commission where such have 
been made. In a few cases, however, these laws have been disregarded, as, 
for instance, in the case of Amoeba, Holothuria, and Physalia, and for the 
reason that it seems probable that in such cases the scientific names of the 
animals which are now in common use will by common consent be retained. 
The author has no desire to be an innovator in this book in the use of 
zoological names, but wishes only to use those which will probably in the 
future be the names of the animals described. 

The name of the author of each species and genus follows the first 
mention of it in the descriptions, as is customary, and in those cases in 
which the author originally placed his species in some other genus than 
the one here employed, his name is in parentheses. Wherever an author's 
name appears more than once in the same genus it is usually abbreviated 
after the first occurrence. No other abbreviations occur in the text except 
in the case of LinnaBUs. In all cases where his name appears as the author 
of a generic or specific name it is abbreviated to "L." 

The illustrations which have been introduced have been copied mostly 
from textbooks, special treatises, and monographs, for the use of which 
hearty thanks are here extended to their authors, whose names appear in 
parentheses after the titles of the figures. Thanks are also due to the 
following publishers for permission to make these copies: Doubleday, 
Page ft Company, Gustav Fischer, Ginn ft Company, Henry Holt ft Com- 
pany, The Macmillan Company, and The Whitaker ft Ray-Wiggin Company. 

In compiling this book the author has utilized every source of informa- 
tion within his reach and is consequently under obligations to very many 
people and their published works. His personal obligation to all those 
friends who have given valuable advice and assistance, often at the expendi- 
ture of much time and labor, is very great indeed. The following are those 
to whom he feels a special indebtedness: Mr. Nathan Banks, Dr. H. L. 
Clark, Prof. W. R. Coe, Dr. C. B. Davenport, Prof. J. H. Gerould, Prof. 
L. von Graff, Prof. C. W. Hargitt, Prof. G. T. Hargitt, Prof. J. S. Kingsley, 
Prof. R. von Lendenfeld (deceased), Prof. A. Looss, Dr. M. M. Metcalf, 
Prof. E. L. Mark, Prof. S. O. Mast, Prof. J. P. Moore, Dr. T. Odhner, 
Dr. A. E. Ortmann, Prof. R. C. Osburn, Dr. H. A. Pilsbry, Prof. A. A. 


Schaeffer, Mr. E. L. Shaffer, Dr. C. W. Stiles, Dr. F. B. Sumner, Prof. 
A. L. Treadwell, Dr. T. W. Vaughan, Prof. D. D. Whitney, Prof. H. H. 
Wilder, Prof. S. R. Williams, Prof. H. V. Wilson, and Prof. R. H. Wolcott 
The author wishes to thank Prof. J. P. Givler of Southwestern College 
for assistance in revising the proof sheets, he having read a large part of 
the text and made many corrections and useful suggestions. He also wishes 
to acknowledge his indebtedness to Prof. Ludwig von Graff of the University 
of Graz, Austria, who extended to him the use of his laboratories and 
extensive library during a residence of two semesters in that city, and whose 
unfailing courtesy and kindness will ever be gratefully remembered. His 
greatest obligation, however, in preparing this work is to Dr. Charles B. 
Davenport of Cold Spring Harbor, Long Island, at whose suggestion it 
was undertaken in the first place, and without whose constant cooperation 
from year to year during its progress it would not have been completed. 

H. S. P. 
Haverford, Penn. 


Iktkoductioh 1 

1. The Linnaean system of classifying animals 1 

2, The study of animals in America 5 

syhopsis of ihyebtebbate akimalfl 

1. Protozoa 11 

Class 1. Sarcodina 14 

Class 2. Mastigophora 24 

Class 3. Sporozoa 42 

Class 4. Infusoria 48 


Subphylum 1. Spongiaria 71 

Class 1. Calcarea 75 

Class 2. Hezactinellida 77 

Class 3. Demospongiae 78 

Subphylum 2. Cnidaria 86 

Class 1. Hydrozoa 90 

Class 2. Scyphozoa 125 

Class 3. Anthozoa . . . . 132 

Subphylum 3. Ctenophora 150 

Class 1. Tentaculata 151 

Class 2. Nuda 154 

Phtxtjm 3. Vebmes 155 

Subphylum 1. Plathelminthes 156 

Class 1. Turbellaria 157 

Class 2. Trematodes 171 

Class 3. Cestodes 189 

Class 4. Nemertea 203 

Subphylum 2. Nemathelminthes 213 

Class 1. Nematoda 214 

Class 2. Gordiacea 225 

Class 3. Acanthocephala 228 

Subphylum 3. Trochelminthes 230 

Class 1. Rotifera 230 

Class 2. Oastrotricha 243 

Class 3. Einorhyncha 244 



Subphylum 4. Bryozoa 245 

Class 1. Entoprocta 246 

Class 2. Ectoprocta 248 

Subphylum 5. Brachiopoda 264 

Subphylum 6. Phoronidea 270 

Subphylum 7. Chaetognatha 271 

Subphylum 8. Sipunculoidea 272 

Class 1. Sipunculida 273 

Class 2. Priapulida 276 

Phylum 4. Annelida 277 

Class 1. Archiannelida 280 

Class 2. ChfiBtopoda 281 

Class 3. Hirudinea 315 

Class 4. Myzostomida 321 

Phylum 5. Abthkopoda 323 

Class 1. Crustacea 326 

Class 2. Arachnoidea 400 

Class 3. Tracheata 461 

Phylum 6. Mollusoa 478 

Class 1. Amphineura 482 

Class 2. Scaphopoda 490 

Class 3. Gastropoda 492 

Class 4. Pelecypoda 563 

Class 5. Cephalopoda 602 

Phylum 7. Eohinodermata 614 

Class 1. Crinoidea 619 

Class 2. Asteroidea 623 

Class 3. Ophiuroidea 633 

Class 4. Echinoidea 638 

Class 5. Holothurioidea . 646 

Phylum 8. Ohordata . . . j 652 

Subphylum 1. Enteropneusta 652 

Subphylum 2. Tunicata 655 

Class 1. Larvacea 657 

Class 2. Thaliacea 660 

Class 3. Ascidiacea 663 

Subphylum 3. Leptocardia 671 

List of Authors 675 

Glossary 693 







1. The Linnaan system of classifying animals.— The foundation of 
the modern system of classifying animals was laid by Carolus Linnaras 
in the tenth edition of his Systema Naturae, published in 1758. In this 
epoch-making work he first applied his fully developed binomial method 
of classification to the animal kingdom and arranged all the animals 
then known to science according to its rules into classes, orders, genera, 
and species. 

The essential feature of this system and that which was new at the 
time was the giving of two names to each species of animals, instead of 
one, or several, one of which was the specific name and the other the 
name of the next higher subdivision in the classification, the genus. The 
other important features were the precisions of the terminology employed, 
which enables the author to characterize a species in a few words, and 
the natural arrangement of the classification in which the position of 
each species indicates the degree of its genetic relationship to all the 

It is true that predecessors of Linnaeus had anticipated many features 
of his system. The idea of a species was already well fixed before his 
time, and efforts were made to characterize those then known and the new 
ones which were constantly being discovered. But the names given were 
often complex and cumbersome and no uniformity existed between the 
systems of terminology of different authors. Also the custom of giving 
two or more Latin names to a species was frequently in vogue, but a 
binomial system, with the definite relation of the specific to the generic 
name, was new. The genus, which gives the clue to the natural affinities of 
the animal, was peculiarly Linn*ms> invention. 

Attempts had also been made by Ray and Klein and other advanced 
thinkers to form a system which should express the natural relationships 



of animals, but such attempts were not generally understood or followed, 
and most authors still employed unnatural methods of arranging them. 
Many still followed Pliny and grouped animals according to their environ- 
mental conditions, placing those together having similar methods of life, 
as land animals, fresh-water animals, marine animals, flying animals, 
etc. Within each group the species were often arranged in alphabetical 

Linnaeus' system was very quickly accepted by the scientific world 
and went into universal use, and modern zoology may, in a very real sense, 
be said to begin with the year 1758. 

So radical, however, was Linnaeus' reform that neither the superiority 
of his system nor the simplicity of his terminology would probably have 
been sufficient thus to procure its instant adoption if they had not been 
proposed by a man of his great fame and commanding position in the 
world. Linnaeus was considered by his contemporaries, because of his 
numerous and important contributions to science and his eminence as & 
teacher in the University of Upsala, as the greatest naturalist of all time. 
His importance was indicated by the phrase in vogue: Deua creavit; 
Linn<su8 disposuit. 

The immediate acceptance of the Linnaean classification had the same 
effect upon the study of animals and plants in his day as that of Darwin's 
theory of natural selection had almost exactly one hundred years later. 
It gave a tremendous impetus to every branch of biological investigation 
and started a new era. Systematic zoology, morphology, physiology, and 
experimental zoology all attracted able investigators, who studied them 
with feverish activity. Comparative studies first became possible as now 
the facts of the science were for the first time arranged in something like 
an orderly and natural manner, and the next generation saw the rise of the 
sciences of comparative anatomy, paleontology, and comparative embry- 
ology, and also the first modern speculations on the blood relationships and 
the evolution of living things. 

All these things gave a new importance to zoology and raised it from 
the position it had occupied of a mere annex to medicine to the dignity of 
an independent science. 

Linnaeus divided the animal kingdom into six classes: Mammalia, 
Aves, Amphibia, Pisces, Insect a, and Vermes. The knowledge of this last 
class, which included all invertebrate animals except the arthropods, was 
in a very confused state and one of the chief objects of the many able 
zoologists of the generation immediately following him was to remedy this 
condition. The men whose services were greatest in this direction were 
0. F. Miiller, Lamarck, and Cuvier. In 1794 Lamarck first distinguished 
the vertebrates from the invertebrates and divided the Linnaean class 


Vermes into the five classes of Mollusca, Insecta, Vermes, Echinodermata, 
and Polypi. Thus a long step was taken towards modernizing the system, 
and this early effort of Lamarck may be said to be the first modern classi- 
fication of animals. He, in his later works, further subdivided the inver- 
tebrate types until he had ten, the fundamental idea at the basis of his 
classification being that the various groups of animals constitute a single 
ascending series which begins with the lowest and ends with the highest. 
This principle of the unity of the type found a wide acceptance among the 
naturalists of that time and was based upon the law: Natura non facit 

In 1812 Cuvier published his subdivision of the animal kingdom into 
four branches or types and in 1817 his great work Le Rigne Animal, which 
established the second great reform of the system, and was destined to 
exert an influence only second to that of Linnaeus' Systema Naturae 
upon the study of animals and the development of the system. In these 
works Cuvier controverted the principle of the unity of type among ani- 
mals and taught that, instead of one, four distinct and permanent types 
prevail. It was upon these four types that he based his four fundamental 
branches of the animal kingdom: Vertebrata, Articulata, Mollusca and 
Zoophyta or Radiata. 

A comparison of this classification with that of Linnaeus will show 
what a tremendous advance had been made in the development of the sys- 
tem in the half-century separating them. The group of animals which 
had benefited most in this general advance was probably the Mollusca, 
which was Cuvier's special field of research. The lowest group in Cuvier's 
system, as in that of Linnaeus, was the one about which the least was 
known, the Zoophyta or Radiata, being made up of several distinct and 
heterogeneous groups of animals which bore no near relationships to one 

This condition led to an active investigation during the generation 
immediately following of all the lower animals, and a very large number 
of works of fundamental importance appeared. Rudoiphi studied the 
parasitic worms, Tiedemann and L. Agassiz the anatomy and Johannes 
Miiller the development of echinoderms, Ehrenberg the microscopic ani- 
mals, Eschscholtz, Sars, and others jellyfish and polyps. The knowledge 
of these two latter groups was also very much extended as the result of 
various scientific expeditions which were sent out by the French, English, 
Russian, and American governments to different parts of the world, espe- 
cially to the' tropical oceans. Of these voyages perhaps the most inter- 
esting were that of the Russian ship Rurik from 1815 to 1818 in which 
Chamisso and Eschscholtz went as naturalists and discovered the alterna- 
tion of generations of Salpa, that of the English ship Beagle between 1831 


and 1835 with Darwin as naturalist, and the American expedition under 
Captain Wilkes between 1838 and 1842 with James Dwight Dana as the 
principal naturalist. 

The influence of all these investigations, and also that of the newly 
established cellular theory of the structure of plants and animals, on the 
development of the zoological system, led to the third great reform of the 
latter. In 1845 von Siebold subdivided Cuvier's fourth type, the Zoophyta 
or Radiata, into three types or phyla, the Protozoa, Zoophyta, and Vermes, 
confining thus the term Zoophyta to the truly radiate animals. He also 
broke up Cuvier's second type Articulata, removing the Annelida to the 
new phylum Vermes and creating another new phylum for the Crustacea, 
Arachnid/a, Myriapoda, and Insecta which he called the Arthropoda, Two 
years later R. Leuckart broke up the phylum Zoophyta, subdividing it 
into the phyla Echinodermata and Ccelenterata, and emphasized the iso- 
lated position of the Protozoa. Milne-Edwards also formed still another 
new type or phylum, the Molluscoidea, in which he included the Bryozoa 
and Tunicata. The animal kingdom was thus in 1850 subdivided into 
eight phyla, the Protozoa, Ccelenterata, Echinodermata, Vermes, Arthro- 
poda, Molluscoidea, Mollusca, and Vertebrata, an arrangement which is 
still found in many textbooks. 

Darwin's Origin of Species was published in 1859 and the fourth 
and last important reform of the zoological system of classification was the 
direct consequence of the doctrines therein promulgated. The theory of 
the common descent and blood relationship of all animals which Darwin 
taught was at variance with Cuvier's theory of fixed types and in harmony 
with Lamarck's theory of the essential unity of the animal kingdom, and 
was first employed by Haeckel as the basis of a system of classification. 
In 1877 he called attention to the need of placing the entire system on an 
evolutionary basis and at the same time subdivided the animal kingdom 
into the two great groups of the Protozoa and the Metazoa, and the 
latter into the two great groups of the Ccelenterata and the Ccelomata. In 
still more recent times other authors, notably Hatschek, following Haeckel's 
lead, have carried the subdivision still further on the same basis. The old 
idea of types, however, has a very tenacious life and is still the basis of 
the classification of animals in most textbooks— and probably rightly so. 
For animals can, as a matter of fact, notwithstanding their ultimate 
relationships with one another, be grouped in a number of distinct types 
or phyla, each of which has a characteristic plan of structure. Cuvier's 
belief, however, that these types are fixed and isolated creations has long 
since been abandoned. 

Very important has been the formation in recent times of the phylum, 
Chordonia or Chordata, which brings under the same subdivision • all the 


animals possessing the essential characteristics of the vertebrate type. 
The formation of this phylum has been due to the fundamental researches 
of Kowalevsky, who in 1866, 1867, and 1871 gave the first detailed and 
accurate descriptions of the anatomy of Balanogloasus and also the first 
detailed account of the embryology of ascidians and of Amphioxus, show- 
ing that these animals are related to one another and to vertebrates. The 
term Chordoma was introduced in 1874 by Haeckel to include the Tuni- 
cata, Amphioxus, and the Vertebrata, and the terms Urochorda and 
Cephalochorda by Lankester in 1878 for the Tunicata and Amphioxtu. 
In 1884 Bateson, on the basis of his researches on the American form 
Balanoglossus aurantiacus, added the Enteropneuata to the Chordata and 
proposed the term Hemichorda. 

The system of zoological classification was thus fixed some twenty or 
thirty years ago and has undergone no important changes in its larger 
features since. This is not true, however, of many of the subordinate and 
smaller of its groups, the arrangement of which changes from time to 
time as the knowledge of the relationships of the animals composing them 
increases. We find this to be especially true of certain low animals 
which seem to be isolated side branches of the ancestral tree, the origin 
of which from the main stem is still obscure. 

2. The study of animals in America.*— The earliest notices of Amer- 
ican animals are to be found in the numerous descriptions of the country 
and books of travel in America which were published in Europe during 
the sixteenth, seventeenth, and eighteenth centuries. In LinnKUs' twelfth 
edition over 500 species of North American animals were described, of 
which 78 were mammals and 260 were birds. Of the authors quoted 
in these descriptions perhaps the most important were Mark Catesby and 
Peter Kalm. The former was an Englishman who lived in the southern 
English colonies of America for about ten years between 1712 and 1726 
and published a large illustrated work on the natural history of the 
region. The latter was one of Linnaeus' pupils who spent the years 
between 1747 and 1751 in Canada and the central English colonies col- 
lecting and studying the native animals and plants for him. IinnsBus 
also obtained much information by correspondence with American nat- 
uralists, especially Dr. Alexander Garden of Charleston, Dr. John Mitchell 
of Virginia, and John Bartram of Philadelphia. Thus in 1766 probably 
most of the larger and more conspicuous animals of the eastern part of 
the country were known to science, as well as many insects and other 
smaller ones. 

• See "A Century's Progress in American Zoology/* by A. S. Packard, Jr., Am. 
Nat Vol. 10, p. 591, 1876. "The Beginnings of American Science," by G. B. Goode, 
Aon. Rep. Smiths. Inst, for 1897, Pt. 2, p. 409. 


Important among the native authors of the period immediately follow- 
ing the Revolution were Thomas Jefferson, who has the distinction of 
being the only American President besides Theodore Roosevelt who has 
been interested in scientific pursuits, Benjamin Smith Barton, and William 
Bartram, the son of John, both of Philadelphia. 

One of the first general works of importance on American animals 
was Wilson's Ornithology (1808-1814). Other similar works belonging to 
nearly the same period were Bonaparte's continuation of Wilson's 
Ornithology (1825-1833), Dr. Richard Harlan's Fauna Americana (1825), 
Dr. John D. Godman's American Natural History (1826-1828), which was 
specially devoted to Mammals, and Audubon's Birds of North America 

During the second and third decades of the century occurred a 
remarkable scientific awakening in the country, an evidence of which was 
the publication of so many works of general interest during this time 
and also the foundation of a large number of scientific societies and 
periodicals. At the beginning of the century there were three promi- 
nent scientific societies in the country, the American Philosophical Society, 
which was founded in Philadelphia in 1743 by Benjamin Franklin, the 
American Academy of Arts and Sciences, founded in Boston in 1780 by 
John Adams, and the Connecticut Academy of Arts and Sciences, which 
was founded in New Haven in 1799. During the first quarter of the 
century many others were founded in various parts of the country, 
and in 1826 no fewer than twenty-five scientific societies were in exist- 
ence, more than half of which were interested principally in natural 

In 1812 the Philadelphia Academy of Natural Sciences was founded, 
and exercised an important influence from the start. The first volume of 
its journal appeared in 1817. Its importance in the first years of its 
existence was due largely to the labors of a single one of its members, 
Thomas Say. This talented young man joined the Academy shortly after 
its foundation and for twelve years, under its auspices, devoted himself 
exclusively to the study of the native animals, the papers he contributed 
to its journal and to other periodicals during this period being funda- 
mental for the study of American mollusks, insects, and crustaceans. 
Another brilliant member of the Academy during this period was Charles 
Alexander Lesueur, a Frenchman who joined it in 1817 and, during the 
seven years that he was a resident of Philadelphia, published many papers 
in its journal on fishes, reptiles, and marine invertebrates. 

Belonging to the same period was another remarkable man, Constan- 
tine Rafinesque. This brilliant and versatile man came to this country 
in 1802 and lived for many years in Philadelphia and in Lexington, 

1NT&0DVCT10N ? 

Kentucky. He was a pioneer botanist and zoologist and is now remem- 
bered by the large number of new species of mollusks and of fishes, as 
well as of plants, which he described. He is also remarkable as being the 
first American who clearly enunciated the principle of the transformation 
of species. 

Philadelphia was during this period the most important scientific 
center of the country, but it was not the only one. The interest in natural 
history was widespread and every city had its public museum of natural 
curiosities and its scientific society. The Philadelphia Museum, which was 
established by Charles Wilson Peale, and the Baltimore Museum estab- 
lished by Rembrandt Peale were especially famous. In the South the 
eminent Georgian Dr. Lewis Le Conte, father of Professor Joseph Le 
Conte, and Stephen Elliott of Charleston were prominent as naturalists, 
and in the west Dr. Robert Best had founded the Western Museum in 
Cincinnati and given the initial impulse to those scientific activities which 
have ever since distinguished that city. 

In New England the principal scientific interest was in geology and 
mineralogy. The most influential scientist was Benjamin Silliman of 
New Haven, a geologist and a chemist In 1818 he founded the American 
Journal of Science and Art which at once became and has since remained 
one of the most influential in the country. 

The fourth and most of the fifth decades were not a period of marked 
activity in the study of American animals. The remarkable development 
of the zoological and physiological sciences in Europe under the leader- 
ship of von Baer, Johannes Miiller, Owen, Milne-Edwards and others 
apparently awakened little interest on this side of the Atlantic and the 
most important investigators were chiefly occupied with descriptions of 
shells and insects. In 1838, however, occurred an event important to 
the development of American science, for in that year the United States 
Exploring Expedition under Captain Wilkes started on its four years' 
voyage, taking as one of its naturalists James Dwight Dana. 

It was in 1846 that light at length began to appear in the general 
darkness and the way to be prepared for the important advances of later 
years in the field of natural science, for in this year the Smithsonian 
Institution, which was to become the center of most important scientific 
activities, was founded under the secretaryship of Joseph Henry, and in 
this year also Louis Agassiz came to America. 

The modern study of animals in America may be said to begin with 
the arrival of Agassiz on our shores. His great reputation and attractive 
and inspiring personality brought him at once into prominence and drew 
to him a large number of brilliant young men who wished to study animals 
under his leadership, and Cambridge and Boston soon became the most 


important center of zoological investigation in the country. Agassiz ele- 
vated these studies to a much higher plane than they had occupied by 
placing them in close touch with European scholarship and also by broad- 
ening and extending them by the introduction of comparative embryology 
and physiology. He also founded and built up the first great zoological 
museum in the country. 

The Cambridge school did not, however, contain all the zoologists in 
the country. In 1846 James Dwight Dana, who had become a Professor 
in Yale and is now remembered rather as a geologist and a mineralogist, 
published his Report on the Zoophytes, and in 1852 his Report on the 
Crustacea of the Wilkes Expedition, both epoch-making zoological works 
and the most extensive works of a monographic nature which up to that 
time had been published by an American. In 1854 appeared the remainder 
of his report on the zoology of this Expedition. Joseph Leidy also, in 
Philadelphia, was beginning his brilliant studies of parasitic worms and 
other small animals. 

The study of shells was followed assiduously in this country during 
this period. Dr. A. A. Gould of Boston, who published the Report of 
the Mollusks of the Wilkes Expedition and also the Invertebrata of 
Massachusetts, Isaac Lea of Philadelphia and A. and W. G. Binney being 
among the most important of the many authors. The study of insects 
was likewise making important advances and T. W. Harris produced his 
Forest Insects, one of the earliest works on economic entomology. 

The most important zoological work of the sixth, seventh, and eighth 
decades of the century was undoubtedly the study of the marine animals 
of our coast by Louis Agassiz and his pupils and followers, of whom 
James McCrady, William Stimpson, Theodore Lyman, Alexander Agassiz, 
Alpheus Hyatt, H. J. Clark, and A. E. Verrill are particularly to be 
mentioned. During the same period J. L. Le Conte, Samuel Scudder, 
C. V. Riley, and A. S. Packard were engaged in the study of insects and 
in laying the foundation of the influential American school of systematic 
and economic entomology, and J. H. Comstock established the department 
of entomology at Cornell which has become a leading factor in the devel- 
opment of the science in this country. Vertebrates were also being 
studied assiduously by E. D. Cope, who in the study of fishes, amphib- 
ians, reptiles, and mammals, and by S. F. Baird and Elliott Coues, 
who, in that of birds and mammals, all produced work of fundamental 

In December, 1873, Louis Agassiz died and with his death ended an 
important era in the history of American zoology—but only to give way 
to another more important. The distinctive school of zoological investi- 
gation which he founded continued to flourish, not only in Cambridge 


under the leadership of Alexander Agassiz and £. L. Mark, but also in 
Baltimore where Louis Agassiz's pupil W. K. Brooks taught in the newly 
founded Johns Hopkins University. From these two centers the scientific 
study of animals has spread to almost all the universities and other institu- 
tions of learning of the country, and the men who have gone out from them 
all year by year in ever increasing numbers have maintained the high stand- 
ards which Agassiz represented and have today placed American scholar- 
ship in this field in the fore rank of the world's achievement. 

Very important in the history of American zoology was the estab- 
lishment, a few years after the death of Louis Agassiz, of the Woods 
Hole Marine Biological Laboratory (1887), The Journal of Morphology 
(1888), and the Morphological Society (1890). These enterprises were 
due very largely to the initiative of C. 0. Whitman and brought about a 
solidarity of interest of the scientific zoologists of the country to which 
the great advances made by zoological investigation in America in recent 
years and the high rank it has attained in the world are largely due. 

Important also has been the part taken by the various scientific de- 
partments of the United States government in furthering the study of 
animals. This work was begun by the Smithsonian Institution in 1846 
and has been continued directly by it and the United States National 
Museum, the Bureau of Fisheries, the Geological and Coast Surveys, the 
Marine Hospital, and the various Bureaus in the Department of Agri- 
culture. The important scientific work carried on by these institutions 
and the great collections they have accumulated have made Washington 
today the most important scientific center in the country. 

3. Subdivisions of the animal kingdom.— The animal kingdom con- 
tains in this book eight subkingdoms or phyla. Several of these are sub- 
divided into subphyla, and all the phyla and subphyla into classes. The 
classes are made up of orders, although they are sometimes first sub- 
divided into subclasses and these into orders. The orders, and the sub- 
orders into which some of them are subdivided, are made up of families, 
and often subfamilies. Each family and subfamily is composed of one 
or more genera and each genus of one or more species. The combination 
of its generic with its specific name constitutes the scientific name of an 

The whole number of species of animals* which make up the animal 
kingdom is not known but probably amounts to several million. The 
number which has been described in scientific publications and given 
names in the Linn©an system of classification is considerably over half 
a million. 

• See "On the Number of Known Species of Animals," by H. S. Pratt, Science, 
K. &, Vol. 35 v p. 467, 1912. 


The following estimates have been made of the number of the 
described species in each phylum: 

Phylum L Protozoa 8,000 

Phylum II. Coalenterata 7,000 

Phylum III. Vermes 9,000 

Phylum IV. Annelida 4,000 

Phylum V. Arthropoda 400,000 

Phylum VI. Mollusca 61,000 

Phylum VII. Echinodermata 4,000 

Phylum VIII. Chordata 37,000 

Key to the phyla of the Animal Kingdom: 

Oa Single-celled animals, aquatic and microscopic 1. Peotozoa 

c, Many-celled animals. 
fc t Body radially symmetrical. 

c t Body with 2, 4, 6 or more, or without, definite radii 2. Cgelenterata 

e, Body with 5 radii 7. Echinodermata 

6 f Body bilaterally symmetrical. 
d Respiratory organs not pharyngeal. 
dt Body without a calcareous shell (with rare exceptions). 

6t Body not externally segmented (except in tapeworms) 3. Vermes 

«, Body externally segmented. 

f x No segmented locomotory appendages 4. Annelida 

/, Paired segmented appendages present 5. Arthropoda 

d, Body with a calcareous shell 6. Mollusca 

Ot Respiratory organs internal and pharyngeal 8. Chordata 


PROTOZOA." (Single-celled Animals. ) 

The Protozoa are minute, aquatic animals which consist each of a single 
cell. The body, like any other animal cell, is a mass of protoplasm con- 
taining one or more nuclei. Distinct organs, in the ordinary sense, are not 
present, but certain specialized structures are usually found in the body 
which perform certain special functions. The Protozoa perform all the 

p, psetidopod 

essential functions which characterize the animal body. The superficial 
layer of the protoplasmic body is usually hyaline and distinct and is called 
the ectosarc (Fig. 2). It secretes in most forms a cuticula or even a hard 
shell which gives the body definite form. In the simplest cases, locomotion 
is accomplished by the thrusting out of projections called psendopodia 
(Fig. 2) in the direction of movement. In the highest forms, however, cilia 

* See "Protoxoa," by O. BQtscbll. Bronn's "KlasseD u. Ord. det Tblerrelcbs," 
Vol I, 1880-1888. "A Lilt of the Protoxoa and Rotifers Found In the Illinois Blver." 
etc., by A. Hempel, Bull. III. St. Lab., Vol. B. p. 301, 1898. "A Report on the Pro- 
toxoa. of Lake Erie." etc., by R. S. Jennings, Ball. D. 8. Fl«b. Com., 1699, p. 10S. 
"Tbe Protoxoa. " bj G, N. Calking, 1901. "Marine Protoxoa ot Woods Bole," hy same. 
Bull. D. 8. Flab. Com., 1901, p. 413. "Tbe Protoaoa of tbe Fresh Waters ot 
Connecticut," by H. W. Coon, Bull. No. 2. State Oeol. and Nat. Hist. Stirrer. "Tbe 
Protozoa of lows," by C. H. Bdmondsoo, Proc. Acad. Bel., Davenport, 1906. "Tbe 
Protoxoa or Sandusky Bay," by F. L. Landacre. Proc. Oblo St. Acad. Bel., Vol. 4, 
p. 421, 1908 (containing a fall bibliography). "Protosoology," by O. N. Calkins, 
1909. "Lebrbncb der Protosoenkunde," by F. Dofleln, 3d Ed., 1911. "Tbe Protosoan 
Parasites of Domestic Animals," by H. Ctawley, Clrc 194, Bur. An. Ind„ Dep. of 
A(., 1912. 



(Fig. 87) or flagella (Fig. 35), which are projections of the ectosarc, are 
present and are permanent organs of locomotion. In a few ciliates true 
muscle fibres are present. Sensation is exercised by the entire surface of 
the body and its projections. 

The inner portion of the body is called the entosarc (Fig. 2) ; in it 
nutrition is carried on. Food in solid form may be taken into the mass of 
the entosarc, where it is usually surrounded by a watery fluid forming the 
food-vacuole, and digested and absorbed. In the lower Protozoa the food 
particles are taken in through the outer surface by a simple process of 
engulfing, no mouth being present, but in most Infusoria a definite mouth 
is present in the ectosarc from which a gullet leads into the entosarc. 
Indigestible portions of the food are thrown out through an anal opening 
in the ectosarc which in the higher forms alone is a permanent structure. 
Many protozoans lead parasitic lives and absorb the vital fluids of their 
hosts through the outer surface of the body. Great numbers of the flagel- 
lates also closely resemble plants in their habits of nutrition. Respiration 
is carried on through the entire outer surface of the body, as is also 
excretion in most marine and parasitic Protozoa. In the majority of 
Protozoa, however, a special excretory organ, the contractile or pulsating 
vacuole (Fig. 2, cv), is present in the form of a minute globule of clear, 
excretory fluid which collects periodically and is then discharged to the 
outside through a temporary opening in the ectosarc. The contractile 
vacuole probably exercises a respiratory as well as an excretory function, 
carbon-dioxide being eliminated by its discharges. 

The characteristic method of reproduction is by equal division. The 
nucleus takes the lead in the process and is quickly followed by the body 
of the cell, and two new individuals are thus formed from a single old 
one. In many Protozoa the new individuals are not completely separated 
from each other, but remain connected together, and a colony is thus 
formed, while in some a physiological division of labor occurs among the 
members of such a colony and an important step towards the development 
of a metazoan animal is taken. Still another modification of simple 
division is the formation of spores, which characterize the Sporozoa and 
occur occasionally in the other Protozoa. Spore formation may be pre- 
ceded by the encystment of the animal and a period of rest; the animal 
draws itself together into as small a compass as possible and then secretes 
a firm membrane or shell within which it lies while spore formation is 
being accomplished. Later the cyst breaks and the spores being liberated 
each becomes a new individual. 

Of universal occurrence among Protozoa is conjugation, or the tem- 
porary or permanent fusion of individuals, which in some of its phases 
resembles the process of fertilization in the higher animals. The two 


individuals which conjugate may he either (1) similar f nil-sized animals, 
(2) full-grown animals of dissimilar size, (3) reduced individuals of similar 
size (similar swarm-spores), or (4) reduced individuals of dissimilar size 
(specialized gametes). In the last mentioned case the gametes resemble . 
the male and female reproductive cells of the Metazoa. 

Conjugation was formerly thought to be a process of rejuvenation by 
which the vital energies of the animals are renewed after the appearance 
of senile changes and a decrease in size and strength. It is now believed 
to be rather a method for the introduction of variation into a race or 
species, and to have thus a meaning similar to that of sexual reproduction 
among the Metazoa, a variable race being better fitted to adapt itself 
to a changing environment and to overcome unfavorable life-conditions. 

The Protozoa are all, with a few exceptions, aquatic animals. When 
the water in which they are living dries up and at certain other times 
they encyst themselves, and in this condition can withstand complete 
desiccation a long time. Protozoa are easily transported by the wind, 
especially when encysted, and many species have a world-wide distri- 

Protozoa feed upon organic matter in every form. Certain species 
are carnivorous; others feed exclusively on plants; many feed on decaying 
substances; and many are parasitic. Of this latter kind many, especially 
among the Sporozoa, are the cause of disease both in man and animals. 
Many contain chlorophyll and live like plants and are 1 consequently near 
the border line between plants and animals. 

H istory.— Microscopic animals were first studied in 1675 by the Dutch 
naturalist Leeuwenhoek, who first used the microscope in the study of living 
organisms. About a hundred years later Otto Friedrich Miiller described 
a large number of them, adopting the binomial nomenclature, and thus 
laid the foundation of the present classification. The name Protozoa 
originated with Goldfuss in 1820, who, however, included in the group 
jellyfish, hydroids, and all of the lowest animals. In 1838 Ehrenberg 
published his epoch-making work on Infusoria, including in this term all 
the microscopic animals, the significance of his work consisting in the fact 
that he brought together accurate descriptions of great numbers of these 
organisms. Ehrenberg was followed by Dujardin and others and in 
1845 von Siebold, interpreting these simple creatures in the light of the 
newly established cell-theory, separated them from the Badiata, with 
which they were classed, and applied to them the name Protozoa. 
Biitschli (1880-1889) gave the classification of the group its present 

The Protozoa contain 4 classes and about 8,000 species, of which the 
majority are radiolarians. 


Key to the classes of Protozoa: 

a l Cilia or flagella absent. 

b t Pseudopodia present, sometimes with rigid, axial filaments. . .1. Sarcodina 

6, Pseudopodia absent, as well as all other locomotor? organs, in the adult 

animal 3. Spobozoa 

a, Cilia or sucking tentacles, or flagella present 

ft* Flagella present 2. Mastigophoba (Flagellata) 

ft, Cilia or sucking tentacles present 4. Infusoria 

Class 1. SARCODINA.* 

The most primitive Protozoa, in which the body is usually with- 
out definite form, but in most cases possesses rigid skeletal structures. 
Locomotion is effected by means of pseudopodia, which are more or less 
temporary projections of the body. In the Heliozoa and Badiolaria these 
are much less changeable in form than in the Rhizopoda and are usually 
supported by a central skeletal filament. Contractile vacuoles are present 
except in the marine forms. Encystment and conjugation characterize all. 
The majority of the Sarcodina are marine animals and they are often 
present in such large numbers in the sea that the empty shells form 
important deposits at the bottom (Foraminifera). The affinities of the 
Sarcodina are with the flagellates : the young of certain forms are flagellate 
and in Mastigamaeba and others the adult form has both pseudopodia and 
flagella. The class was first called the Rhizopoda, but in 1880 Butschli 
substituted the term Sarcodina for Rhizopoda, giving the latter name to one 
of the orders. The class contains 6,000 species, most of which are 
Badiolaria and Foratninifera, grouped in 3 orders. 

Key to the orders of Sarcodina: 

Oj No central capsule present ; animals in both salt and fresh water. 
ft 4 Body naked or with shell, with very changeable pseudopodia which contain 

no central axial filament 1. Rhizopoda 

ft, Body naked or with shell, usually of spherical and relatively permanent form 
with delicate ray-like pseudopodia, each of which contains a central 

filament '. 2. Heliozoa 

a, Central capsule present; marine animals of relatively permanent form with 
ray-like pseudopodia 3. Radiolabia 

Order 1. RHIZOPODA, 

Body usually covered externally by a shell (but sometimes without) 
which is a secretion of the ectosarc, and in many cases is covered with 
sand or other foreign objects; pseudopodia variable in form: 2 suborders 
and about 1,500 species, of which 200 live in fresh and 1,300 in salt water. 

Key to the suborders of Rhizopoda: 

Oj Rhizopoda with simple pseudopodia and with or without a shell. .1. Amojbida 

a, Rhizopoda with branching and anastomosing pseudopodia and with or without 

a shell 2. Reticulabiida 

• Bee "Freshwater Rhizopoda of North America/' by J. Leidy, Rep. U. 8. GeoL 
8ur. t etc^ VoL 12, 1879. 


Suborder 1. AMCEBIDA. 

Rhizopoda having lobose pseudopodia which may be finger-shaped or 
pointed, but are usually not reticulate; shell of chitin or silica usually 
present, to which sand or other foreign bodies may be attached : 3 families. 

Key to the families of Amcebida: 

0} Naked Amcebida 1. Amcsbidae 

a, Amcebida with a shell. 
&i Shell membranous, often with sand and other foreign bodies imbedded in 

it 2. Abcelltoae 

6, Shell composed of regular plates of silica or chitin ; pseudopodia sharp and 
often branching and sometimes slightly anastomosing. . . .3. EueLYPmnAB 

Family 1. AMCEBIDAE. 

Shell-less Rhizopoda, whose pseudopodia are not reticulate; body 
without definite form and under ordinary conditions constantly changing 
its shape by throwing out pseudopodia, although covered by a cuticula of 
greater or less delicacy: about 19 genera, with numerous species in both 
fresh and salt water. 

Key to the genera of Amcsbidae here described : 

Ox Nucleus absent 1. Pbotamoeba 

a. Nucleus present and usually distinct. 

b x Numerous nuclei, vacuoles, and retractile bodies present 2. Pelomyza 

6, Numerous nuclei, vacuoles, and retractile bodies not present. 

Cj Pseudopodia membrane-like, ectosarc reddish 3. Plakopus 

Cg Pseudopodia not membrane-like. 
&x Pseudopodia more or less lobose, sometimes slender and spine-like. 

€i Animals not parasitic 4. Amceba 

e, Animals parasitic 5. Entamoeba 

d\ Pseudopodia very long, radiating spine-like from body. 

6. Dacttlosphjceium 

1. Pbotamceba Haeckel. Minute forms without nucleus or con- 
tractile vacuole, in constant motion, with short pseudopodia: 4 species; 
in salt and fresh water. 

P. primitiva Haeckel. In fresh and salt water. 

2. Pbxomtxa Greeff. Very large forms constantly flowing by 
means of short pseudopodia ; body with numerous nuclei, vacuoles and 
hyaline rods; diameter up to 2 mm.: 4 species; in fresh water. 

P. palustris Greeff. Without projections at hinder end. 

P. villosa Leidy. Possesses numerous posterior projections; about 
1 mm. in length; body dark and opaque. 

P. carolinensifl H. V. Wilson. No rods present, but numerous 
minute crystals; 1 mm. in diameter. 

3. Plaxofus F. £. Schulze. Body changes slowly in form and with 
{Minted pseudopodia which are often joined together by a broad mem- 
brane: 2 species; in fresh water. 


P. ruber F. E. Schulze. Color reddish: in fresh water. 

4. Auceba Ehrenberg. Body may assume a variety of forms, being 
often more or less spherical while at rest ; pseudopodia either slender or 
lobose; nucleus and contractile vaenole present: about 12 species; in 
fresh and salt water. 

A. Umax Dnjardin (Fig. 1). Body small, elongate, without 
definite pseudopodia and moves by slowly flowing along: in fresh 

A. proteus (Pallas) (Fig. 2). Diameter up to £ mm.; pseudopodia 
long and usually blunt; movements often active: in fresh water. 

A, radios* Ehr. Pseudopodia slender and radiating; body more or 
leas star-shaped; diameter about .04 mm.: on water plants. 

Fig. 8 Fig. 1 Big. 8 

Fig. 8 — Awunha timmM (Conn). Fig. 4 — Bntamaha ooU (DoOeln). 

Fig. 6 — Entamaba di/senteriae (Dodcin). 

A. verrucosa Ehr. (Fig. 3). Diameter up to .2 mm.; pseudopodia 
short; surface folded; movements sluggish. 

6. Emtakceba CaBBgrandi and Barhagallo. Similar to Amaba, but 
parasitic in mammals ; size minute ; pseudopodia short and sluggish: 
several species. 

E. coll (Loesch) (Fig. 4). Form roundish or elongate with a dis- 
tinct nucleus and an indistinct ectosarc; pseudopodia short and slug- 
gish; diameter .00 mm.: in human colon; formerly supposed to be a 
cause of dysentery. 

E. uysentoriae (Councilman and Laflenr) (E. histolytica Schandinn) 
(Fig. 5). Similar to E. coli but with a distinct ectosarc: in the human 
colon ; the cause of dysentery. 

6. DAOTTXocPBJgxiDM Hertwig and Lesser. Small round forma 
with often numerous long.ray-like pseudopodia, which sometimes vibrate 
slightly; short and blunt pseudopodia also present when the animal 
moves : in fresh water. 

D. radioium (Ehrenberg). Three or 4 long spine-like pseudopodia; 
diameter .02 mm. 

D. polypodia F. E. Schulze. Numerous finger-like pseudopodia 


Sholl membranous and consisting of a single chamber, the surface 
of which is either smooth or covered with sand or other foreign par- 
ticles; single opening usually present from which blunt pseudopodia 
protrude : fresh-water animals of minute size ; 10 genera and about 30 

Key to the genera of Arceilidae here described: 

«, Shell covered with sand or other foreign bodies 1. Dtjtluqia 

a, Shell Dot covered with foreign bodies. 

6, Shell composed of quadrilateral plates 2. QuADBUELL* 

6, Shell of one piece, not composed of plates. 
c, Shell flexible and more or less disc-like ; 1 to 3 openings. .8. CoCHUOFODTUic 
c. Shell disc-shaped and not flexible. 

A, Rim of shell without spines 4. aa oELLi 

4, Rim of shell with spines C. Cxittboptxib 

1. DrmuoiA Leclerc, Shell covered with sand-grains or other 
foreign bodies, pear-shaped or spherical, frequently with spines at the 
sides or binder end, and with a large opening at the other end from 

Big. o Fig. T Fig. 8 

Flg.fl. — tligiuoia tobeitcma (Conn). Flg.T — DMhnia corona (Leld». 
Fig. 8 — Q uadrueiio n/mmelrlca (Lefdy). 

which a number of blunt pseudopodia may project; nucleus and con- 
tractile vacuoles always present: about 20 species, which are very vari- 
able in form; in fresh-water pools, usually on plants or on the bottom. 
D. loboatOBU Leidy (Fig. 6). Shell spherical or ovate, the oral pole 
truncated; month usually 3 to 6 lobed; aboral end rounded; length .12 

D. pyrifonnia Perty. Shell bottle-shaped with a cylindrical neck 
more or less distinct ; length up to .6 mm. : common. 

D. nrceolata Carter. Shell jug-shaped with short neck and often a 
rim; hinder end pointed or rounded; length up to .52 mm. 

D. constrict* Ehrenberg. Shell ovoid; month oblique; aboral end 
rounded, often with spines; length up to .3 mm. 

D. globnlosa Dujardin. Shell spheroidal or oval; month circular; 
length .2 nun. or less: rather common. 

D. acuminata Eh r. Shell oval; aboral end acute, often prolonged, 
rarely with 2 or 3 points ; length .4 mm. 



D. corona Wallich (Fig. 7). Shell spheroid with a number of long 
spines at hinder end; length up to 32 mm: very common. 

2. Qoaobuxlla Cockerell. Shell 
pear-shaped and composed of quad- 
rilateral silicious plates, with oc- 
casional spines at the hinder end: 
several species; in fresh water. 

Q. symmetrica (F. E. Schulze) 
(Fig. 8). Length up to .14 mm.: 

Fig. 8 — CochliapodluinMliwtloiHm (Lpldy). . 

in swamps. 
3. CooHLiOFODnm Hertwig and Leaser. Shell minute, spheroid or 

, changing in shape: 3 

disc-like, without foreign bodies, and flexible, < 
species; in fresh water. 

0. bilimbosnm Auerbach (Fig. 9). Diameter 
up to .05 mm. ; opening large, the acute pseudopodia 
protruding: among algae, etc., in fresh water. 

0. digitatum Calkins. Several openings through 
which pseudopodia protrude. 

ft. Asoxlla Ehrenberg. Shell yellow or brown 
and smooth, not being covered with sand, convex 
on one side, and flat or concave on the other, in 
the middle of which is the opening; nuclei and 
contractile vacuoles 2 or more: several species; in 
fresh water, also in moist sand and moss. 

A. vulgaris Ehr. (Fig. 10). Diameter about .15 mm.; 
scalloped: very common. 

A. dentata Ehr. (Fig. 11). Diameter about J8 mm.; margin scal- 


; margin not 

— Aroella dentala 

Fig. \Z—Eutilyp>ia alveolata 

Fig. 1! — Centropuvt* aculeata (Leldy). 


5. Gxntbopyxh Stein. Shell similar to Areella, but with spines, 
variable in number, and sometimes elongate: in ditches and pools, 
0. aculeata Stein (Fig. 12). Diameter of shell .2 mm, 



Shell membranous and composed of plates of chitin or silica 
enclosing a single chamber with a single large opening; pseudopodia 
filiform and sometimes somewhat anastomosing ; size minute : 5 genera ; 
mostly in fresh water. 

1. EtTOLTFHA Dujardra. Shell elongate, ovate, often with spines 
at hinder end and composed of oblique rows of round plates whose 
edges overlap, making hexagonal areas; opening denticulate; pseudo- 
podia fine, often branching but not reticulate: in fresh water; 4 

E. alveolate Dnj. (Fig. 13). Shell colorless, elongated 
and cylindrical; hinder end broader, usually with a few 
long spines; plates composing it are round or oval; length 
.15 mm.: common, 

E. dilate Leidy. Shell elongate and elliptical in 
cross section; hinder end and sides with numerous short 
spines; plates six-sided; length .1 mm.: common in 
sphagnum moss. 

2. Gxfhosota Schlumberger. Shell retort-shaped 

and composed of minute plates; opening turned to one gig. 14 

side; forward half of body contains numerous contractile Cvphoieria 
vacuoles, and hinder half the nucleus; color yellowish: (Leidy). 

2 species; in fresh and salt water. 

0. ampulla (Ehrenberg) (Pig. 14). Length .17 mm.: in ponds and 


Pseudopodia filiform and reticulate; calcareous shell usually pres- 
ent which has either one or more large openings or many minute ones, 
through which the pseudopodia project : 3 divisions. 

Key to the divisions of Reticulariida : 

a, No shell present 1. Nuba 

a. Shell with one or more large and no minute openings 2. IMPEBFOHINA 

a. No large but numerous minute openings 3. PEETOBJNA 

Division 1. NUDA. 

Rbizopods without shell and with reticulate pseudopodia: about 8 
genera; mostly marine. 

Biomtxa Leidy. Form incessantly changing; nucleus present or 
apparently absent: 1 species. 

B. vagina Leidy. Color pale gray with oil globules, nucleus when 
present large and distinct; no ectosarc: in sphagnum moss. 


Division 2. mPBBFORIVA. 
RhiEopods with shell which has one or more Urge openings from 
which project reticulate and anastomosing pseudopodia; shell usually 
calcareous, but sometimes membranous, to which sand may adhere, and 
one or many chambered: 4 families. 

Marine and fresh-water rhizopods with a membranous shell with 
an opening at one or both ends: 10 genera. 

Key to the genera of G romiidae here described : 
a, Shell with but one opening. 
b, Pseudopodia richly anastomosing ; contractile vacuoles usually present. 

1. Obohu 
6, Pseudopodia anastomosing- little ; numerous contractile vacuoles. 

2. PaitPHAona 
a. Shell with an opening at each end 3. Diploprstb 

Fig. IS — ammia lagmoldM (Calklna), 

1. Oboiha, Dnjardin. Shell spherical or ovate in shape and entirely 
filled by the protoplasmic body; shell membranous and often flexible, 
changing its shape; pseudopodia very fine and reticulate; nuclei one or 
many: several species; in fresh and salt water. 

Q. lagenoides Gruber (Fig. 15). Body about .25 mm. long, with 
opening at larger end of shell; edge of opening turned in; a fine layer 
of protoplasm surrounds the shell which has flue reticulata pseudopodia 
on all sides of it; shell either with or without foreign bodies: Woods 
Hole; not numerous. 

2. PAXPKAGtTB Bailey. Psendopodia very delicate, springing from 
a common protoplasmic base and not anastomosing; shell flexible and 
delicate, and filled by the protoplasmic body ; opening of shall narrow : 


P. lantaWlfa Bailey. Body compressed and ovate or pear-shaped; 
protoplasm yellowish in color; length 1 mm.: in swamps. 

P. hyalinus Leidy. Body almost spherical with short neck; often 
colonial; length .04 mm. 

& DmoPHBYi Barker. Shell spherical and membranous and with 
two openings opposite each other, from which protrude the pseudopodia: 
2 species; in fresh water. 

D. archer! Barker. Pseudopodia not always anastomosing; length 
.02 mm. 

Division 3. PEBFOBINA. (Pobaiunitiba.) 

Calcareous shell, either one or many chambered, and with numerous 
minute pores, as well in some cases as large openings, through which 
stream reticulate pseudopodia: 9 families with numerous genera and 
over 1,200 species, most of which live in the mud of the sea bottom, about 
20 species being pelagic 


Shell calcareous and one or many chambered with one or more large 
openings: about 7 genera. 

GxoBXonnrA D'Orbigny. Shell with many chambers which are 
more or less ovoid and spirally arranged; large openings crescentic; 
usually with spines: about 13 species; marine. 

G. buILoides D'Orb. Animals pelagic and also in the bottom mud 
at all depths down to 3,000 fathoms: cosmopolitan. 

Obdkb 2. HELIOZOA.* 

Sarcodina with little power of amoeboid movement, with a siHcious 
skeleton and fine ray-like pseudopodia which are often supported by 
silicious axial filaments; ectosarc and entosaro usually sharply marked; 
contractile vacuole present in the fresh-water forms, but absent in the 
marine ones; either one or several nuclei present; reproduction either 
by equal division or by spore formation, the spores being flagellate 
and after an active life losing their flagella and assuming the form of 
the adult; conjugation and encystment also occur: about 50 species, 
grouped in 4 suborders; mostly in fresh water, but also in the sea and 
in moist earth. 

Key to the suborders of Heliozoa: 

«! Heliosoa without skeleton. 

ft ft Body naked 1. Aphbothobacida 

a, Body with a soft gelatinous or felted fibrous covering. .2. Chlaicydophobida 
a, Heliosoa with skeleton. 

b t Skeleton consists of spicules 3. Ohalabathobacida 

ft, Skeleton consists of a single piece perforated by numerous openings. 

4. Dkbmothobacida 
• See "Hello**," by F. Schaadlnn, Das Tlerreleh, 1806. 


Naked Eelioeoa with filiform pseudopodia radiating from all sides 
which are either with or without axial filaments; one or more nuclei 
and contractile vacuoles present: 9 genera. 

Key to the genera of Aphrothoracida here described : 
a, Body more or leas amceboid. 
A, Ectoearc and entosarc sharply defined ; animals appear on algae as red 

cysts 1. Vamptezlla 

6, No boundary between ectosarc and entosarc 2. Nucleahia 

o, Body not amceboid ; form spherical. 
b, Ectosarc and entosarc not denned ; skeletal axis of pBeudopodia extending to 

center 3. ACTINOPHBYS 

6, Ectosarc and entosarc abarply separated 4. Actinosfh^ebiuk 


Fig. 18— aottnoiBftwrfNM elchhornt I 

1. Vamfyreixa Cienkowsky. Ectosarc hyaline; entosarc brown or 
red, frequently vacuolated; form amoeboid, pseudopodia radiating from 
all sides or arising from only one place: 5 species; in fresh and salt 

V. lateritia Leidy (Fig. 16). Body spherical or elongated; diameter 
about. .06 mm. ; length of moving animals may be .24 mm. : among fresh- 
water algae. 

2. NpoxeabUl Cienkowsky. Body spherical or elongate and amoe- 
boid with homogeneous protoplasm; pseudopodia radiating from all sides 
or arising from only one place; one or more nuclei and many contractile 
vacuoles: 2 species; in fresh water. 

N. simplex Cienk. Diameter about .05 mm. : among Spirogyra and 
other fresh- water plants. 

3. Actimophsyb Ehrenberg. Body spherical and not amoeboid; 
pseudopodia radiating from all sides and with axial threads which 
extend to center of body; ectosarc and entosarc not separate: 1 species; 
in fresh and Bait water. 

A. sol (0. F. Muller) (Fig. 17). Diameter .05 mm.; often colonial: 


4. AoTDfOSPKSBnnc Stein. Like Actinophrys but with sharply 
defined and vacuolated ectosare: 1 species. 

A. eichhorni (Ehrenberg) (Fig. 18). Diameter up to 1 mm.: in 
fresh water; common. 


Body spherical and with a soft gelatinous or felted covering in 
which foreign bodies may be present: 5 genera. 

Hbtsbophbts Archer. Body with a slight differentiation into 
ectosare and entosarc; pseudopodia radiating from all sides: 2 species; 
in fresh and salt water. 

H. myriapoda Archer. Diameter .08 mm.; pseudopodia twice as 
long as diameter of body; chlorophyll bodies often present: in fresh 
and salt water. 


Isolated silicious needles present which cover the outer surface: 8 

1. Raphtdiophrys Archer. Body spherical, covered with silicious 
needles lying tangentially; ectosare and entosarc not distinct; pseudo- 
podia with axial threads radiating from all sides ; often forming colonies 
which have a common covering: 4 species; in fresh water. 

R. elegans Hertwig and Lesser. Diameter .04 mm.; often with 
chlorophyll bodies: in fresh water. 

2. Aoavthoctbtis Carter. Spherical animals in which the silicious 
needles project radially; between them are the thread-like pseudopodia, 
each with an axial thread; tangential needles may also be present: 10 
species; in fresh water. 

A chaetophora (Schrank). Diameter .1 mm.; needles of 2 forms, 
a short and a long, both forked, and both with basal plates. 


Body enclosed in a silicious spherical shell containing numerous 
round holes; a central nucleus; many contractile vacuoles and filiform 
pseudopodia: 2 genera. 

Olathrtjltka Cienkowsky. Body spherical and fastened by a stalk 
to some fixed object; the body does not fill the shell, which is absent in 
the young individuals : 2 species ; in fresh water. 

0. elegans Cienk. (Fig. 19, p. 24). Diameter of shell .07 mm.; length 
of stalk up to .3 mm.: in pools. 



Marine Sarcodina often of large size, with ray-like pseudopodia; 
Bilicioua skeleton present in most cases, which is often of great com- 
plexity and beauty; pseudopodia usually with axial 
filaments; body divided into two regions, the central 
capsule and the extra capsular portion ; /capsule sur- 
rounded by a perforated ebitinous membrane' and oc- 
cupying tbe center of the body containing also one or 
more nuclei and often oil globules; extra-capsular proto- 
plasm often vacuolated and pigmented and containing 
often yellow unicellular algae (zooxanthellae) which live 
symbiotically in it; no contractile vacuole present; re- 
production by division, the central capsule dividing first ; 
in some forms the central capsule alone divides, and a 
colony is the result; spore formation has also been ob- 
served, in which flagellate spores are formed in the 
Pig. 19 central capsule : about 85 families and over 4,300 species, 

OI «taf!<M* M which are found mostly in the deep sea. 


Skeleton wanting; central capsule simple, with a single nucleus. 
TxauuiooLLA Huxley. Extra-capsular portion filled with alveoli 
among which are numerous yellow algae. 

1*. pelagica Haeekel. Diameter 2 mm. : in the Mediterranean. 

Class 2. MABTIOOPHOEA. (Flaqellata.) 
Protozoa whose motile organs consist of one or more long whip-like 
projections called fiagella. The body is provided with an external mem- 
brane which, in many cases, is very delicate, the body being more or 
less amteboid. A membranous shell of silica, chitin, or cellulose is also 
often present In one group, the Choanoflagellida, the base of the single 
flagellum is surrounded by a high ridge called the collar (Fig. 28). A 
single nucleus is present, and usually a contractile vacuole. 

The protoplasm usually shows no division into eetosarc and entosare. 
It often contains cbromatopbores which may be formed of chlorophyll 
and green, or of diatomin and yellow or brown in color. Other bodies 
allied to starch or oil are often present imbedded in the protoplasm. 
Reproduction is by division and by spore formation; colony formation, 
the result of incomplete division, is very common, the members of tbe 
colony being sometimes enclosed in a common cellulose jelly, sometimes 
connected by protoplasmic strands, and sometimes joined by both jelly 


and strands. The colony is in some cases very complex with division 
of labor among the different individuals. 

The Mastigophora have been known from the earliest period of 
the study of microscopical animals under the general name of Flagellata, 
and are still so known in many textbooks. The name Mastigophora 
was given the group by Biitschli in 1883. The animals live in both 
fresh and salt water, and many are parasites in the higher animals, 
being often the cause of disease. Large numbers closely resemble 
plants and many are on the border line between animals and plants. The 
class contains 3 subclasses with about 350 species. 

Key to the subclasses of Mastigophora: 

9% Small Mastigophora with a definite anterior and posterior end, at one or the 
other of which are 1 or more flagella 1. Flaoellidia 

Ob Mastigophora with usually 2 flagella, 1 anterior and 1 transverse in posi- 

a, Large marine Mastigophora with parenchymatous protoplasm. 

3. Otstoflagkludia 

Subclass 1. FLAOELLIDIA. 

Body with a well-defined cuticula which gives it a definite shape, 
the cuticula in some forms, however, being so thin that changes in shape 
often take place; pseudopodia formed in certain forms; many flagel- 
lates are protected by external coverings of jelly, chitin, silica or 
cellulose; 1, 2 or several flagella extend from one end of the body, 
usually the forward; in the Choanoflagellida, however, the single flagel- 
lum is at the hinder end and is surrounded at its base by a collar: 8 
orders, in which are included the great majority of flagellates, very 
many containing chromatophores and being apparently allied to plants. 

Key to the orders of Flagellidia: 

*i Body colorless, often more or less amoeboid, and with one or more flagella. 
*i Body spiral with or without flagellum, and more or less like bacteria. 

1. Spibochetida 
6, Body not spiral. 

e, One flagellum with collar present 3. Chqanofl a qkt.t.tda 

c, No collar present. 
o\ Body with indistinct cuticula, often more or less amoeboid. 

4 Body elongate with undulating membrane 5. Thypanosomatida 

e» No undulative membrane present. 
/i Two or more flagella, one directed forward, the other trailed behind. 

4. Hetebomastioida 
f % Flagella always directed forward. 

g x One or two flagella ; body usually more or less amoeboid. .2. Monadida 

g t Three or more flagella 6. Polymastigida 

4, Body with distinct cuticula 7. Euglknida 

Ob Body usually either yellow or green, often colonial. 

fct Body with distinct cuticula, and usually solitary 7. Euglentda 

a, Body usually with a hyaline, gelatinous or cellulose house ; colonial. 

8. Phttoflaoeixida 



Body elongate, spiral, with or without an undulating membrane; 
flagellum very short or absent; nucleus diffuse: 1 family. 


With the characters of the order: 3 genera. 
1. Spzbooxeta Ehrenberg. Undulating membrane but 
no flagellum present: about a dozen species; 
mostly parasitic. 

8. balbianii (Certes) (Fig. 20). Length .02 
to .18 mm.; broad membrane present; ends 
rounded: in the digestive tract of the oyster, 
often in the crystalline style. 

8. plicatilis Ehr. (Fig. 21). 
Length .08 to .2 mm.; narrow 
membrane present; ends rounded: 
in stagnant water. 

Fig. 20 Fig. 21 _ _ _ , __, „« »« 

i* io-m***. MM- 2. Tukpohkka Schaudmn. Fla- Fig. 22 

Fig. £3faSi- plic* ^ llum but no adulating mem- T X 
tills (Dofleln). brane present: about 8 species. (DoMn). 

T. pallidum Schaudinn (Fig. 22). Body cylindrical, without 
membrane, .015 mm. long; ends tapering, ending each in a fine flagellum: 
in syphilitic lesions. 

Order 2. MONADIDA. 

Body usually without shell and more or less amoeboid, with 1 or 2 
large flagella at the forward end and often 1 or more secondary flagella; 
no mouth : 5 families. 

Key to the families of Monadida here described : 

Ox Pseudopodia present 1. Rhizomastigidax 

a, Pseudopodia absent. 
bx One flagellum present. 

Ox Body not in a cap 2. Ceboomonadidab 

c, Body in a cup 3. Codonbcidaje 

b t Two flagella present 4. Hetebomonadidajc 


Simple forms without mouth and with 1 or 2 flagella; occasionally 
with either lobose pseudopodia like a rhizopod or stiff radial ones like 
a heliozoan; food taken at any part of the body: -6 genera. 

Mastioaikeba F. E. Schulze. Body irregular in form with several 
pseudopodia which disappear when the animal swims, and one long 
flagellum: 6 species; in fresh and salt water. 


M. verrucosa Kent (Fig. 23). Length about .015 mm.; many short 
pseudopodia: in fresh water. 

M. simplex Calkins. Ectosarc and entosare distinct; flagellnm 

converted into a pseudopodium ; length .01 mm.: marine, on decaying 



Body oval or elongate, frequently amoeboid, especially at hinder 
end;. with pseudopodia and with a long flagellum: 5 genera. 

1. CBE00X0HA8 Dujardin. Form more or less spindle-shaped, pro- 
longed posteriorly: 3 species; in fresh water. 

C. longicanda Duj. Tail long; length up to .05 mm. 

Fig. 23 Fig. 24 Flg.26 

Fig. 23 — Mastigamaba verrucosa (Calkins). Fig. 24 — Herpetomonas muscae 
domesticae (Doflein). Fig. 25 — Codoneca gracilis (Calkins). 

2. Hxbpetomohas Kent. Body elongate, very flexible; hinder end 
often the more attenuate, but not forming a caudal filament: several 
species; parasitic in insects. 

H. muscae domesticae (Burnett) (Fig. 24). Length .05 mm.: in 
intestine of the house-fly; common. 

3. Oisomohas Kent. Form spherical or oval; frequently a pro- 
jecting lip at base of flagellum; sometimes attached by a terminal fila- 
ment : several species in fresh and salt water, often in infusions. 

O. termo (Ehrenberg). Length .06 mm.: often very common in 
fresh water. 


Body enclosed in a gelatinous or hyaline cup: 2 genera. 

Oodovsoa Clark. Ovoid or goblet-shaped, and attached to a caudal 
stalk; animal does not fill cup: 3 species; in fresh and salt water. 

C. gracilis Calkins (Fig. 25). Cup urn-shaped with a distinct neck; 
length .021 mm.: Woods Hole. 


One or 2 accessory flagella present besides the main one; often 
sessile or colonial, the animals being on a common stalk: 3 genera. 


Key to the genera of Reteromonadidae: 

Ot Solitary forme 1« Mowas 

o, Colonial forma, 

ft* Common stalk branched once or twice ; on Cyclops. . 2. Cbphalothakniuh 
ft, Common stalk much branched. 3, Anthofhysa 

1. Mohab Ehrenberg. Body spherical or ovate, occasionally fast- 
ened by a thread-like stalk; 2 flagellar 3 species; in fresh water. 

Flg.26 Flg.27 Flg.28 

Fig. 26—: M anas elongata (Conn). Fig. 27 — Cephalothamnium cmpitowm (Conn). 

Fig. 2&—ManoHg* ovata (Calkins). 

M. elongata (Stokes) (Fig. 26). Body elongate; hinder end tapers 
to form stalk; length .01 mm. 

2. Cepkalothaxhiux Stein. Body ovate, with one long and one 
short flagellum; animals colonial and sessile, the stalk branching two 
or three times and several individuals being grouped at the end of each 
branch: 2 species; in fresh water, often on Cyclops. 

C. caspitosum (Kent) (Fig. 27). Body with obliquely truncated 
anterior end; length of individual .02 mm. 

3. Avtkopktsa Bory. Body as in above; stalk much branched: 
1 species; in fresh water. 

A. vegetans (0. F. Miiller). Length of individual .03 mm., of 
colony .4 mm. 


Collar flagellates. Collar-like ridge surrounding the base of the 
single flagellum which is at the hinder end of the body when the animal 
swims, instead of at the forward end as in other flagellates; in some 
forms 2 collars are present, one over the other: 2 families. 


Either solitary or colonial and either free-swimming or sessile and 
often enclosed in a cup or a gelatinous envelope: 4 genera. 
Key to the genera of Craspedomonadidae : 

<K Shell wanting; animals sessile or stalked. 

bx Stalk shorter than body or wanting 1. MoNOSlOA 

Oa Sulk long, with many individuals at the end 2. Codonosioa 

6, SUlk long, branched at end 3. Codonogladium 

a, Shell present 4. Salpingodca 


1. Momosiga Kent. Small colorless forms, solitary and sessile, 
attached directly or by a short stalk: 9 species; in fresh and salt water. 

M. ovata Kent (Fig. 28). Individual ovate or spherical; length .08 
mm.: in fresh and salt water. 

2. Oodonosiga Clark. Similar to Monoaiga, but at the end of a 
stalk and solitary or colonial: 1 species. 

0. botrytU dark. From 1 to 20 individuals in a colony; length of 
individual .08 mm., of stalk .014 mm. : in fresh and salt water. 

3. Oodohocladiux Stein. Like Codonoaiga, but the stalk branches, 
each branch bearing an individual: 4 species; in fresh and salt water. 

O. umbellatum Stein. Number of branches 4 to 10, which some- 
times also branch; length .03 mm.: in fresh water. 

4. BaxrorcKEOA Clark. Solitary; body enclosed in a shell, usually 
cup-shaped, which is directly attached at base or at the end of a short 
stalk: about 27 species; in fresh and salt water. 

8. steini Kent. Shell cylindrical; length .02 mm.: in fresh water. 


Two or more flagella present, one of which is directed forwards and 
the others backwards, during locomotion; no shell present; animal 
colorless: 2 families. 


Small, naked forms with 2 flagella of nearly equal length : 4 genera. 
Key to the genera of Bodonidae here described : 

<h Flagella spring from anterior end. 

b, Flagella longer than body, which is ovate * 1. Bono 

ft, Flagella shorter than body, which is elongate 2. Phtllomitus 

a, Flagella spring from a lateral groove 3. 

Fig. 29 Fig. 80 Fig. 31 

Fig. 29— Bodo caudatu* (Calkins). Fig. 30— PfyHomitiM amylopJiaffue (Conn). 

Fig. 81 — OayrrhU marina (Calkins). 

1. Bono Ehrenberg. Body more or less ovate, often amoeboid; 
anterior end pointed, with 2 flagella arising from a slight depression : 10 
species; in salt and fresh water. 

B. caudatus (Dujardin) (Fig. 29). Body ovate, often amoeboid; 
flagella about the same length; length .018 mm. 


2. Phyllokitus Stein. Body elongate and very flexible, with 2 
flagella shorter than the body: 1 species. 

P. amylophagus Klebs (Fig. 30). Length .018 mm.: in fresh water. 

3. Oxybbhis Dnjardin. Body oval with pointed hinder end, at 
side of which is a deep cavity from which the flagella emerge: 1 species; 

0. marina Duj. (Fig. 31). Length .04 mm.: at Woods Hole. 


Body elongate, usually pointed, with an undulating lateral mem- 
brane and 1 or 2 flagella which arise from a special nucleus (blepharo- 
plast) and accompany the membrane as a lateral chord: 1 family. 


With the characters of the order: several genera; parasitic in 
invertebrate and vertebrate hosts and often the cause of deadly diseases. 

Fig. 32 Fig. 83 Fig. 34 

Fig. 32 — Trypanosoma gambiense (Dofleln). Fig. 33 — Trypanosoma brucei (Dofleln). 

Fig. 34 — Hewamitus inftatus (Conn). 

Trypanosoma Gruby. But 1 flagellum present: over 60 species, 
which are parasites of the blood system in all kinds of vertebrates and 
are also found in the intestine of various blood-sucking insects, which 
in many cases are known to convey the parasite to the vertebrate host 
by their bite. 

T. gambiense Dutton (Fig. 32). The cause of the deadly sleeping 
sickness which affects man in western and central Africa; it is conveyed 
by Glo8sina palpate, a tsetse fly ; length .03 mm. 

T. brucei Plimmer and Bradford (Fig. 33). The cause of nagana, a 
sickness fatal to horses and cattle and other animals in Africa and is 
conveyed by Glossina morsitans, a tsetse fly. 

T. evansi Steel. The cause of surra,* a fatal disease to horses and 
cattle in Africa, Asia, and America and conveyed by horse flies. 


Three or more flagella and usually several mouth openings present; 
body colorless and without shell : 3 families. 

• See "Collected Studies on the Insect Transmission of Trypanosoma evansi/' by 
M. B. Mitimaln, Ball. 94, Hyg. Lab,, Wash., 19X4. 



Flagella in two symmetrical groups, with a mouth at the base of 
eaeh: 2 genera. 

Hexamitus Dujardin. Body ovate, with 2 to 4 flagella at forward 
end and hinder end prolonged into 2 thread-like processes: 3 species; in 
fresh water, also parasitic in intestine of amphibians. 

H. inflatns Duj. (Fig. 34). Posterior processes not close together; 
length .027 mm. 

Order 7. ETJGLEN1DA. 

Large forms with usually a distinct, spirally striped cuticula; 
1 or 2 flagella present at the forward end, with a so-called 
pharynx at their base and a contractile vacuole opening into the 
pharynx; frequently colonial and usually colored by chromatophores 
in which 1 or more deeply staining bodies, the pyrenoids, may be 
present; paramylum, a substance allied to starch, also usually present: 
3 families. 

Key to the families of Euglenida: 

«, Chlorophyll usually present 1. Euglenidae 

a, Chlorophyll absent 

b t Without distinct month ; saprophytic 2. Astasiidae 

o, With distinct mouth ; holozoic 3. Pabakeiodae 

Family 1. EUGLENIDAE. 

Body spindle or pear-shaped with usually a single flagellum; chloro- 
phyll, pyrenoids, and paramylum and an eye-spot almost invariably 
present; contractile vacuole or vacuoles open into a reservoir which 
opens into the pharynx; nutrition mostly holophytic, in some cases 
saprophytic: 6 genera. 

Key to the genera of Euglenidae: 

<h With one flagellum. 
©t Cnticula elastic, animals more or less plastic, 
c, Animal not in a shell. 

&i Animal free-swimming 1. Euglena 

d, Usually attached to other animals 2. Colaciuic 

c, Animal in a shell 3. Trachelomonas 

6, Cuticula not elastic and animal not plastic. 

Ox Chromatophores disc-shaped 4. Phacus 

c, Chromatophores in two longitudinal bands 5. Cbtftoglena 

a, With two flagella 6. Eutbeptia 

1. Ettglena Ehrenberg. Large spindle-shaped flagellates with 
spirally marked cuticula; 1 flagellum, at the base of which are the 
pharynx, eye-spot, and contractile vacuole; color usually, green or 
red, a few being colorless: species numerous; in fresh and brackish 


E. viridia Ehr. (Fig. 35). Length .1 mm. or lese; bod; lenticular: 
often very common in pools, which it may color green. 

E. teas Ehr. Body very long, even filiform, pointed behind ; length 
.18 mm. 

E. dews Ehr. Body elongate, .2 nun. long, with nearly 
parallel aides: common. 

2. OoLAonnc Ehrenberg. Like Evglena, but usually 
attached by a short stalk at the forward end to small ani- 
mals; flagellum present in free-swimming condition, but 
usually not present when attached: 3 species; in fresh water. 

0. steini Kent. On Diaptomus; length .04 mm. 

3. TsACHXLOMOaTAa* Ehrenberg. Like Euglena, except 
the animal has a brown or colorless shell: numerous species; 
in fresh and salt water. 

T. lagenella Stein. Shell ovoid or cylindrical and 
smooth; length .03 mm. 

T. hisplda (Perty). Shell ovoid, covered with spines 
and usually dark brown in color; length .03 mm. 
Bujlma T - armata Ehr. (Fig. 36). Shell brown, punctate; 2 

(DofleLu). rovs °f spines around aperture and spines often around 
posterior end; length .04. 

4. Phacds Nitzseh. Body somewhat asymmetrical, flattened or 
pear-shaped, with spiral strips; binder end spine-like; chromatophores 
disci-shaped : 6 species; in fresh water. 

p. pyrnm (Ehrenberg) (Fig. 37). 
Body top-shaped; length .03 mm. 

P. lomrlcaudns Dujardin. Hinder 
spine very long; length .08 mm. 

5. Cbyptoglkita Ehrenberg. Body 
oval, rigid, with 2 lateral green chromato- 
phores and an eye-spot : 1 species. M - T^sto-urna. I " 

0. pigra Ehr. Length .015 mm.: in * p * lmt £ M J i fc™^ kao *' 
fresh water. 

6. Eutmptia Perty. Like Euglena, but with 2 flagella; body very 
flexible; chromatophores disc-shaped: 1 species. 

E. viridls Perty. Length .05 mm.: in fresh water. 
Family 2. A8TASITDAE. 

Elongated, colorless, more or less amoeboid flagellates without eye- 
spot and usually with striped membrane; sometimes with an accessory 
flagellum: 6 genera. 

• 8m "Delaware Valley Form* of Trschelomonas," bj T. C. Palmer, Proc Acad. 
Nat 8d., 1B05. 


Key to the genera of AatasUdae here described : 

^ Body very flexible 1. Astasia 

«, Body rigid, sickle-shaped 2. Meivoidium 

1. Astasia Ehrenberg. Body spindle-shaped; very 
plastic, with striped cuticula: 2 species; in fresh and salt 

A. contorta Dnjardin (Fig. 38). Length .06 mm.: 
in decaying vegetation. 

2. Hevoidium Perty. Body elongate and more or 
less bent, and rigid; cuticular stripes longitudinal: 1 

M. pellucidum Perty. Length .08 mm.: in fresh 

water. Fig. 88 

Family 3. PERANEMIDAE. Astasia 


Body usually cylindrical or ovate, plastic or rigid, **' 

and covered by a striped cuticula; 1 or 2 flagella present, at the 
base of which is a distinct mouth; no chlorophyll present: 14 

Key to the genera of Peranemidae here described : 

«! Body plastic. 

&i Body elongate, attenuated forward 1. Pebanema 

b\ Body bottle-fihaped 2. Uboeolus 

a, Body rigid ; two flagella. 

hi Pharynx not deep 8. Anisonema 

ft* Pharynx very deep 4. Entosiphon 

1. Pebahzma Dujardin. Body tapers from behind 
forward and very plastic, with a spirally striated cuticula 
and a single flagellum, the tip of which vibrates when the 
animal moves: 1 species. 

P. trichophorum (Ehrenberg) (Fig. 39). Length .08 
mm.: in fresh water. 

2. Urosoltts Mereschkowski. Body spherical or ovate 
with a neck from which the flagellum emerges : 
1 species. 

U. cyclostomus (Stein). Length .03 mm.: 
in fresh water. 
P!_ gg 3. Ajtisokema Dujardin. Body ovate and 

Peranema compressed with striated cuticula and a „ ', * 
(C&nT lateral groove; 2 flagella, 1 of which trails ^CoSST 
behind: 3 species; in fresh and salt water. 
A. vitrenm Duj. Body transparent and with longitudinal furrows; 
length .05 mm. 


4. Evtoszpsov Stein. Body ovate, with 2 flagella of nearly equal 
length, one of which trails behind, a deep ventral furrow and a very 
deep pharynx: 2 species. 

B. sulcatum St. (Fig. 40). Length .02 mm. : in fresh and salt water. 


Flagellates which include most of those forms with holophytic or 
saprophytic nutrition, and are often classed as plants; most of them 
are enclosed in a cellulose shell or jelly; yellow, green or brown chro- 
matophores usually present ; very many are colonial : 4 suborders. 

Key to the suborders of PhytoflagelUda here described : 

Ox Yellow chromatophores usually present 1. Chboicomonadiwa 

a% Green chromatophores usually present. 

6 t Mostly non-colonial ; 2 or 4 flagella 2. Chlamydomonadina 

6, Colonial ; 2 flagella 3. Volvogina 


Flagellates with a delicate cuticula and often somewhat amoeboid, 
which are usually enclosed in a shell or jelly, and are often colonial; 
yellowish or bluish chromatophores and 1 or 2 flagella present: 2 

Key to the families of Chromomonadina: 

Ok Color yellowish ; no pharynx present 1. Chrysomonadidab 

o. Color blue, green or brown, or colorless ; deep pharynx present. 

2. Cryftomonadidae 


Body usually with a shell or in a jelly, with 1 or 2 flagella and always 
with 1 or 2 yellowish chromatophores, and with or without eye-spots; 
nutrition usually holophytic: 15 genera. 

Key to the genera of Chrysomonadddae here described: 

o» Body in a shell which it does not fill 1. DrNOBBYON 

a, Body in a shell which fits it closely. 

6t One flagellum 2. Mallomonas 

o. Two flagella. 

Cj Flagella of equal length 3. Syitora 

c, One flagellum long, one short ; colonial 4. Uroglena 

1. Dihobbyov Elirenberg. Free-swimming branched colonies, each 
individual of which is in a transparent cup-shaped shell which springs 
from just inside the opening of the shell next behind it; 2 flagella of 
unequal length, 1 or 2 yellowish or brownish chromatophores, and an 
eye-spot present: 3 species; in fresh water. 

MJ.8T1G0PH0RA 35 

D. sertnlarla Ehr. (Fig. 41). Shell .04 mm. long: in fresh water, 
often in great quantities; sometimes fouls the water in reservoirs and 

2. Maxlomokab* Perty. Free-swimming and solitary, with closely 
fitting reticulated oval shell bearing long spines; 2 yellowish chromato- 
phores; without eye-spot; 1 flagellum: several species in fresh water, 
which may produce an odor and injure water supplies. 

M. punctifera (Ehrenberg). Spines all over shell; length .035 nun. 

3. SYinrHA Ehrenberg. Swimming spherical colonies of about 50 
radially arranged individuals; each individual with 2 flagella, 2 brown 
chromatophores, eye-spots and sometimes spinose: 1 species. 

S. uralla Ehr. (Fig. 42). Length of individual .03 mm,: in fresh 

4. Uroslsva Ehrenberg. Swimming spherical colonies composed 
of many individuals in a jelly; individual pear-shaped, with 2 unequal 

flagella, 2 yellow chromatophores, and an eye-spot: 2 species; in fresh 

U. americana Calkins (Fig. 43). Length of individual .006 mm.: 
the cause of the fishy taste of the water in some reservoirs. 


Body with a firm cutieula and not amoeboid ; 2 equally long flagella, 
at the base of which is a long pharynx extending to the middle of the 
body; 2 chromatophores present or absent: 3 genera. 

Key to the genera of Cryptomonadidae : 
a, Without chromatophores. 
a, A row of highly refractive bodies in forward part of bodr...l. Cyathomomab 

6, Without such bodies .2. Cbilomonas 

o, With chromatophores 3. Cbtptomohas 


1. Otathomovas Fromentel. Body colorless, ovoid, flattened, with 
obliquely truncated forward end, with 2 flagella of nearly equal length; 
parallel with the anterior border is a row of highly retractile bodies: 
1 species. 

0. truncate (Fresenius) (Fig. 44). Length .023 mm: in fresh 
water and infusions. 

2. Chilomonas Ehrenberg. Body colorless, oval, compressed; for- 
ward end obliquely notched, with two equally long flagella: 2 species; 
in fresh water and infusions. 


Fig. 44 Fig. 45 Fig. 46 

Fig. 44 — Cyathomonas truncata (Conn). Fig. 45 — Chilomonas Paramecium (Conn). 

Fig.46—Chlamydomonas pulvisoulus (Conn). 

C. Paramecium Ehr. (Fig. 45). Body ellipsoid; length .03 mm.: 
very common. 

3. Obtftomovas Ehrenberg. like Chilomonas, but with 2 green or 
brown chromatophores : 2 species; in fresh and salt water. 

0. ovata Ehr. Length .03 mm.: in fresh water, to which it may 
give a fishy taste. 


Body green in color with 2 or 4 flagella and usually a firm cuticula 
or shell within which division takes place: 2 families. 


Cuticula very delicate with no large pores: 7 genera. 

1. Ohlaxtdoxonas* Ehrenberg. Body spherical to cylindrical 
with 2 flagella and an eye-spot, a delicate shell, prominent chromato- 
phores and 2 contractile vacuoles: about 6 species; in fresh water. 

C. pulvisculus Ehr. (Fig. 46). Body spherical, about .02 nun. in 
diameter: in fresh water, to which it gives an oily flavor. 

2. Spohdtlomorum Ehrenberg. Colony of 16 cells in 4 alternating 
rows, each cell with 4 flagella: 1 species. 

8. quaternarium Ehr. Diameter of colony .05 mm. : in fresh water. 

3. Polttoxa Ehrenberg. Body ellipsoid with a delicate shell and 
flagella, colorless, occasionally with an eye-spot; 2 contractile vacuoles; 

• Bee "Chlamydomonas and Its Effect on Water Supplies," by O. C. Whipple, 
Trans. Am. Micro. Soc, Vol. 21, p. 97, 1900. 


reproduction by division into 4 or 8 cells, which remain in the shell and 
then become free: 2 species. 

P. nvellnm Ehr. (Fig. 47) . Length .02 mm. : in 
fresh water. 

Suborder 3. VOLVOCINA. 


Colonial flagellates, the individual cells of uveiium (Conn?* 

which have each 2 flagella, an eye-spot and green 
ehromatophores, and are imbedded in a common cellulose jelly; repro- 
duction sexual and asexual: 7 genera, all represented in America; in 
fresh water. 

Key to the genera of Volvocina: 

Ox Colony in form of a plate. 
6 t Flagella on one side only of colony. 

Ct Colony squarish 1. Gonium 

c, Colony round with a spheroid envelope 2. Stephanosphjera 

b, Flagella on both sides 5. Platydorina 

a, Colony spherical or ellipsoidal. 
&! Colony microscopic. 

Cj Cells crowded, reaching center of colony 3. Pandortna 

c, Cells not thus crowded. 

<*! Cells alike in size 4. Eudobixa 

d, Anterior cells small, posterior ones large 6. Pleodorina 

b t Colony not microscopic and composed of a large number of cells. . .7. Volvox 

1. Qoim 0. F. Miiller. Colony of few and similar individuals 

forming a squarish plate with the flagella on one 
face only; asexual reproduction by repeated divi- 
sion of all the cells, each forming a new colony; 
sexual reproduction the result of the conjugation 
of pairs of similar individuals, the zygotes thus 
formed, after a resting stage, each developing into 
a colony: 2 species, 1 American; in fresh water. 

Kg. 48 O. pectorals O. F. Mul. (Fig. 48). Colony 

Gonium pectorale consists of 16 cells and .06 mm. in diameter: 



2. 8xKFKAV08FKJOtA Cohn. Colony consisting of 4 or 8 cells ar- 
ranged in a ring which is surrounded by a large rounded envelope of 
which the cells form the equator ; reproduction as in Gonium : 1 species. 

8. plovialis Cohn. Envelopes up to .06 mm. in diameter. 

3. Pahdo&IVA Bory de Vincent. Colony more or less spherical, 
composed of 16 or 32 crowded cells which reach the center and are sur- 
rounded by a lamellate envelope; reproduction as in Gonium, except that 
the conjugating cells may differ slightly in size : 1 species. 


P. momm Bory. (Fig. 49). Colony up to .09 mm. in diameter: 

4. Eudobisj. Ehrenberg. Colony more or less spherical, composed 

usually of 32 (occasionally of 16 or 64 cells) which are 
not close together and do not reach the center, and 
are surrounded by an envelope; asexual reproduction 
as in Gonium; at certain times sexual colonies appear, 
the female being like the ordinary colony, the male 
colony consisting of long, spindle-like cells which be- 
come free and unite with the female cells forming the 
Fl*. 49 zygotes : 2 species. 

Pandorinamonm E. elegant! Ehr. (Fig. 50). Colony about .15 mm. 

in diameter: cosmopolitan. 

5. Platydobima* Kofoid. Colony flattened, horseshoe-shaped, com- 
posed of 16 ot 32 cells with the nagella on both faces on alternate cells 
which are alike; asexual reproduction as in Gonium; sexual reproduction 
not observed : 1 species. 

P. caudata Kofoid (Fig. 51). Colony about .15 mm. long and .13 
mm. wide ; posterior end of envelope with 3 or 5 tails : Illinois. 

6. Puodokxxa Shaw. Colony more or less spherical, composed of 
16 to 128 cells, certain of which are reproductive and the rest vegeta- 
tive, the former being twice the size of the latter, and posterior in 
position; asexual reproduction as in Gonium; sexual reproduction not 
observed: 2 species; both in America. 

P. calif ornica Shaw. Cells 64 or 128, half of which are vegetative: 

P. ttlinoisensist Kofoid (Fig. 52). Cells 32, rarely 16 or 64, 4 of 
which are vegetative, .12 mm. in diameter: Illinois. 

• See "On Platjdorlna," etc, by C. A. Kofoid. Ball. 111. St Leb., Vol. 6, 
p. 419, 1899. 

t Bee "On PleodorlM IlllDoliensfs," etc., by C. A. Kofoid, III. St. Let>„ 
Vol. D, p. 273, 1898. 


7. Voivox* L. Colon; forms a hollow sphere of large size and 
composed of hundreds or thousands of cells connected by protoplasmic 
threads, and not differing in size; asexual reproduction by so-called 
parthenogonidia which are cells in the center of the colony (1 to 9 in 
number), which form there by repeated division daughter-colonies ; at 
certain times sexual cells appear, the androgonidia and gynogonidia, 

which retire to the center of the colony where 

the latter are fertilized by the former and 
after a resting period the zygotes develop into 
new colonies: several species; in all parts of 
the world. 

V. globator L. (Fig. S3). Colony of 1,500 to 

22,000 cells and up to 1.2 mm. in diameter: pro- «.»__. 

' r ' r Big. BS— Volvom 

toplasmio threads may contain chromatophores: rahasSf'T 


V. aureus Ehrenberg (V. minor Stein). Colony of 200 to 4,000 
cells and np to .85 mm. in diameter; protoplasmic threads contain no 
chromatophores: cosmopolitan. 


Flagellates in most cases with a shell, around the equator of which 
is a transverse groove in which lies a flagellum; a second fUgellum is 
also in most cases present, which may spring from a second and vertical 
groove; body sometimes colored by chromatophores: 3 orders. 

Key to the orders of Dinoftagellidia here described : 

a, No transverse groove ; 2 flagella at forward end 1. AoiHIDA 

a, Two grooves, a transverse and a longitudinal 2. Diniixbida 

Ordeb 1. ADLNTDA. 

Body without groove ; 2 flagella at the forward end ; shell composed 
of a right and a left half: 2 genera. 

1. Exvtolla Cienkowsky. Body ovoid, shells compressed and 
composed of right and left valves; 2 brown chromatophores present: 5 
species; marine. 

• See "New Forma of Volvox," by J. H. Powers, Tranl. Am. Hlc. Soc, Vol. 2T, 
p. 123. "Light Reactions la Lower Organism! — II Volsoi," bj 3. O. Must, Jour. 
Comp. Ntor. and Par., Vol. IT, p. 99, 1907. "Le Volvox," liy C. Janet, 1912. 

t See "New Species ot DinoflagelUtM," by C. A. Kofold, Bull. Mm. Com. Zool., 
Vol. SO, p. 183, 1907. "Dlnoflagellata of the San Diego Region," by aatne, TJniv. at 
CaL Pub. ZooL, Vol. 8, p. 299, 1907. 

E. lima (Ehrenberg) (Fig. 54). Anterior border of both shells 
slightly indented; length .04 mm.; slow of movement: at Woods Hole. 


Two grooves present, a transverse and a longitudinal: 2 families. 

Key to the families of Dituferida: 

a. Transverse groove near middle of bod; 1. Pesidihida-B 

Oi Transverse groove above the middle 2. Dinophtbidai 

Transverse groove medium; longitudinal groove short; shell, when 
present, composed of plates or not; plates either equatorial (bordering 
the transverse furrow), apical, or antiapieal, while a rhombic plate may 
extend from the transverse furrow to the apex: about 4 genera. 

Key to the genera of PeHdinidae .- 
a. With shell, 
ft, Reticular markings on shell. 
o, Anterior part of shell with 7 equatorial and 1 rhombic plates. 

1. PsaiDINTOM 

e. Anterior part of shell with 3 equatorial and no rhombic plates. 

2. Cekattum 

6, No markings on shell 3. Glknodin«um 

Ot Without shell 4. GiicltoniNiux 

1. PEEiDiHnnt* Ehrenberg. Body globular or elongate; shell with 

distinct transverse groove, which may be spiral and with about 20 

plates: 9 species, fresh and salt water; many species are reddish in 

color and may be in sufficient numbers to color the sea. 

P. digitale Ponchet (Fig. 55). Shell with large 

pits and with oblique furrow, 1 posterior and 2 

anterior spines; length .06 mm.: Woods 

Hole; marine; common. 

P. divergans Ehr. Shell spherical, 
tapering posteriorly, with 2 large spines 
anteriorly; length .07 mm.: Woods Hole; 
marine; common. 

2. Cs&ATnmt Schrank. Body a 
flattened sphere with 3 long projections; «*•«> 

Pig. fH — Ecuufeda transverse groove either spiral or cir- aiottait 
Rata (Calkins). , ,__ -I ,. , „ (Calkin.), 

cular; longitudinal groove usually wide; 

shell reticulate or striped and composed of 10 plates; color usually green 
or brown: numerous species; in fresh and salt water. 

* Bee "Peridlnlnm and the 'Red Water* In Narragansett Bar," by A. D. Mead, 
8d. N. 8.. Vol. 8. p. 70T, 1898. 

t Bee "Mutations In Ceratlam," br C. A. Kofold, Bull. Hub. Comp. Zool., Vol. G2, 
p. 213, 1900. 

MA8T1G0PB0RA 41 

0. tripos Ehrenberg (Fig. 56). Body triangular with 1 very long 
and 2 short curved projections; length .29 mm.: Woods Hole; marine; 

very elongate, due to presence of 2 long 
line; length .28 mm.: Woods Hole; marine; 

projections in the i 

3. QraoDOrnrx Stein. Small globular forms with a transverse 


VlS. Cfl — Carta Hum Iriflo 

> (Calkins). 

groove on anterior half and a short longitudinal one; shell soft and 
structureless and without markings: 6 species; in fresh and salt water, 

Q. compressnm Calkins (Fig. 57). Body ovoid, compressed, with 
deep transverse and longitudinal grooves; hinder end often pointed and 
this point becomes attached; length .04 mm.: Woods Hole. 

4. OntMODnmrM Ehrenberg. Body without shell and spherical, 
sometimes pointed or flattened: 8 species; in fresh and salt water. 

(J. gradle Bergh (Fig. 58). Transverse groove in anterior half; 
longitudinal groove long; color brown; length .06 mm.: Woods Hole; 


Transverse groove near upper end of body, its edges as well as edge 
of the longitudinal groove being usually produced into 
characteristic ledges. 

1. Akphidimtum Claparede and Lachmann. Body 
ovoid and flattened; longitudinal groove extending from 
hinder end to transverse groove near forward end; shell 
absent; color, brown or green: 2 species; in fresh and 
salt water. 

A. operculatnm CI. and Lach. (Fig. 59). Length .04 
mm.: Woods Hole. 

Marine flagellates of large size with a parenchymatous protoplasm: 
several genera. 


Nootxlvoa Suriray. Body spherical and 1 mm. or less in diameter! 
with a median groove in which lies a large feeler and a small flagellum, 
as well as the mouth; single nucleus present; reproduction by division 
and by spore-formation: 1 species; marine. 

N. miliaria Sur. In the Atlantic and Pacific Oceans; often so plen- 
tiful that the sea is colored red by day and glows by night with an 
intense phosphorescent light. 

Class 3. SPOBOZOA.* 

Parasitic protozoans which live in the cells, tissues, and open spaces 
of other animals. The body is usually bounded by a thick cuticula; it 
has no external openings or contractile or gastric vacuoles, and in most 
cases but one nucleus. In the adult condition there are no organs' of 
locomotion, although the animals have often the power of sluggish 
movement. Being entoparasites, all Sporozoa absorb food in a fluid 
or gaseous form through the outer surface of the body. Reproduction 
is carried on through the medium of spore formation, which usually 
follows encystment, the reproductive processes being in many forms 
very complex. Simple division does not occur. The Sporozoa are very 
widely distributed, living as parasites in every class of animals from 
Protozoa to Veriebrata: they are often the cause of disease both in 
man and the lower animals. The class contains two subclasses and 
about 400 known species, besides about as many uncertain species. 

Key to the subclasses of Sporozoa: 

0t Sporozoa in which spore formation ends the individual life, including the great 
majority of the class 1. Telospobidia 

o» Sporozoa in which the entire cell does not form spores but sporocysts are 
formed during life 2. Nbospobidia 

Subclass 1. TELOSPORIDIA. 

In these Sporozoa the individual life ends with spore formation, 
the entire cell forming spores: 3 orders. . 
Key to the orders of Telosporidia: 

0! Parasitic as adults in the open spaces and organs of the host. .1. Grkgarxnida 

Os Parasitic in the solid tissues and not the open spaces 2. Coccidiida 

a, Parasitic in the blood of vertebrates 3. HasMOSPoamiiDA 


Usually elongate Sporozoa with a thick cuticula and a distinct 
nucleus; life history includes two stages, an attached stage, when the 
animals are known as cephalonts, and a detached and sporulating stage, 

• See "Sporosoa," by A. Labte, Das Tierreich, 1899. 

8P0R0Z0A 48 

when they are called sporonts and live in the open spaces of the organ 
to the walls of which they have been attached; body in moat cases 
made up of two or three parts (Fig. 65), the epimerite at the forward 
end, which in tbe organ of attachment of the eephalont and may be 
dropped by the sporont, and the body, which may be divided by a septum 
into the deutomerite which forma tbe bulk of the body and contains the 
nucleus and the protomerite which lies between it and the epimerite: 
about 300 species grouped in 2 suborders. 

Key to the suborders of Gregarinida: 
a, Gregarinee with an epimerite, and with or without a septum between the 

deutomerite and protomerite 1. Cephaijha 

a, Gregarinea without epimerite and consisting of a single chamber. 


Suborder 1. CEPHALINA. 
Gregarines possessing an epimerite at 
some stage of their life which is sunk 
into the walls of the organs of the 
host in which they live; body usually elon- 
gate, the animals being often in associated 
couples or groups arranged tandem, in 
which ease the first individual is called the 
primite and the others the satellites: in 
arthropods as adults, especially in the intes- 
tine of myriapods, beetles and Ortkoptera; 
10 families and about 100 species. rJ^'tD^wZ^^VVnai 

Key to the families of Cephalina here ffiS&£&j$£.fTgti 
described: c ' BDore - 

«, Spore more or leas ovoid 1. GreoaBINIdae 

o, Spore not ovoid. 

ft, Epimerite asymmetrical 2. Daottlophobidae 

6, Epimerite symmetrical. 

c, Spore symmetrical, animal solitary 3. Actinocephalidae 

c, Spore asymmetrical. 

d, Spore crescent-aba ped ; animal solitary 4. Mbnospobtdae 

d. Spore ovoid with polar thickening; in marine annelids.. 6. Dolioctstxdab 

Individuals either associated, forming a chain with a septum sep- 
arating each two individuals, or solitary; epimerite simple and sym- 
metrical: 8 genera and about 35 species. 

• Bee "Lilt Of tbe Polycyrttd Cregarlnes of tbe United State*," by H. Crawley, 
Proc. Acad. Nat. Bel., Vol. SB, p. 41, 1903. "Tbe Polycystic! (IregarlneB of tbe United 
States," by H. Crawley, same, p. 632. "Movement* of tbe Otvgarlnee," same. Vol. ST, 
p. 80. "Study ot Same Oregarlnea," etc., by M. C. Hall, Stud, from Zool. Lab. Univ. 
Neb, No. 77, 1907. "Tbe Polycystld Oregarlnea of tbe United States." by H. Crawley, 
Proc Acad. Nat Sel., 1B07, p. 230. 



Fig. 61 





Key to the genera of Gregarinidae here described: 

Ox Individuals usually associated 1. Greqabtna 

a, Individuals usually solitary 2. Stenophoba 

1. Gbegabxha Dufour. Individuals usually associated; epimerite 
simple and small but varying in form, being conical or spherical; cysts 

spherical or ovoid, when ripe with long projections called 
sporoducts through which the spores emerge: about 20 
species; in the digestive tract of insects. 

G. blattarum von Siebold (Fig. 60). Body elongate 
but somewhat irregular; cyst ovoid with long sporo- 
ducts; length about .5 mm.: in the intestine of the 

G. achetae-abbreviatae Leidy (Fig. 61). Deutomerite 
ellipsoidal or oval; protomerite hemispherical; animals 
solitary or in pairs; length .5 mm.: in the common 

G. melanopli Crawley. Protomerite cubical or flat- 
tened; deutomerite more or less rectangular; length .37 
mm.: in intestine of the grasshopper. 

G. locustae-carolinae Leidy. Protomerite globular on 
which the epimerite appears as a small round knob; 
deutomerite globular; length .35 mm.: in intestine of the 
large grasshopper, Dissosteira Carolina. 

2. Stenophoba Labbl. Body large, ovoid or elongate; 
cyst without sporoducts ; protomerite small : 4 species. 

8. jnli Frantzius (Fig. 62). With the characters of the genus; 
protomerite often conical: very common in the intestine of Julus. 

Fig. 62 




Epimerite asymmetrical and irregular, with digitiform processes: 

5 genera. 

1. EOHnroMERA Labb6 (Echinocephalus Schnei- 
der). Body ovoid and massive; epimerite conical 
with the apex excentric and varied in form: 
1 species. 

E. hispida (Schneider) (Fig. 63). Deutomerite 
eight or ten times as long as the other two divi- 
sions; animal very active: common in gut of 

2. Tbioho&htvohtts Schneider. Protomerite cylindrical or trun- 
cated with a long rostrum: 1 species. 

Fig. 63 Fig. 64 

Fig. 63 — EcMr 
nomera hispida (from 
Bronn). Fig. 64 — 
Amphoroides f Onta- 
rio* (Crawley). 


T. pulcher Schneider. In the intestine of Scutigera; length .07 mm. 


Solitary animals with symmetrical epimerite; spores symmetrical 
and spindle-shaped: 17 genera and about 27 species. 

1. Amvhobozdes Labbe. Epimerite simple and regular, with a 
eonieal point; protomerite very short and cup-like; spores biconical: 
2 species. 

A. fontariae Crawley (Fig. 64). Deutomerite a long oval, hinder 
end being always blunt; protomerite circular or pen- 
tagonal; length JL3 mm.: in diplopods of the family 
Polydesmidae; often numerous. 

2. Astekophora Leger. Epimerite mucronate and 
elongate; protomerite usually larger than the deutom- 
erite: 3 species. 

A. cratoparis Crawley (Fig. 65). Deutomerite lance- 
olate, terminating bluntly; protomerite round with a Fig. 65 
conical projection in front; epimerite small, consisting of Asterophora 
a number of ribs; length .5 mm.: in curculionid beetles. (Crawley). 


Epimerite large, joined by a long neck with the 
protomerite; spores crescent-shaped: 2 genera. 

Hofloshyhcuub Cams. Animals solitary; elliptical 
in shape; epimerite with 6 to 8 long marginal teeth: 
2 species. 

H. actinotus (Leidy) (Fig. 66). Deutomerite conical 
with a pointed hinder end; protomerite small, tending to 
fuse with the deutomerite; epimerite long, with a large 

Fig. 66 


ch** spreading front end; length .5 mm.: in Scolopocryptops, 

(Crawley). a diplopod. 


Deutomerite not separate from protomerite : spore ovoid, with polar 
thickening: 1 genus. 

Douootbtxs Leger. With the characters of family: 6 species. 

D. rhyncoboli Crawley. Deutomerite long, tapering to the hinder 
end; protomerite and epimerite small: in the intestine of Rhynchobolus 



Subobdbb 2. ACEPHALIHA. 

Ho epimorite present, the body consisting of a single chamber; 
spore Hpiiidle-bhaped : about 10 genera and numerous species, whioh live 
principally in the body cavity 
of the host and the organs con- 
nected with it. 

MoMOOTsns Stein. Body 
ovoid or elongate, sometimes 
with long cntienlar filaments; 
individuals mostly solitary: 
about 10 species. 

FIC-ST — lfonooturH* Wmtrini (from Rrono). __ i__t,_i_j ,-a i \ 

A, tingle individual; B, a spore; M. lumbriCi (Henlo) 

5 * CT ' t ' (M. agitie Stein) (Pig. 67). 

Length 2 nun.: in intestine, genital organs and ocelom of the earth- 
worm; common. 

H. clymenollae* Porter. In the body wall of ClymeneUa torquata. 

Obdeb 2. OOOOIDriDA. 

Spomioa of spherical or ovoid shape without a free stage, which 
live imbedded in the solid tissues of the host, usually as intracellular 
parasites; reproduction by sporulation with an 
alternation or generations: 5 families and 70 

Bmon Schneider (Coccidium Leuckart). 
Cyst ovoid, each on sporulation forming 4 sporo- 
blasts, each of which produces 2 spores: 13 

E. stiedaa (Iindemann) (E. outtfciiZi Rivolta) ^2* TSttstuii apt- 
(Pig. 68). In the liver and other organs of 

rabbits and other animals, also in the human liver; length of cyst 
.04 mm. 


Sporozoa parasitia in the blood of vertebrates, with or without a 
change of hosts; reproduction occurs by asexual spore-formation usually 
in the body of some other animal where conjugation takes place fol- 
lowed by pseudosexual spore-formation: about 4 genera. 

1. Plasmodium" Marchiafava and Celli. An intra-oorpusoular para- 
site in mammalian blood corpuscles where it finally breaks up into about 
12 asexual spores (merosoites) which are often grouped about a central 
* Be* 'Two New Gnaarinlda," by 1. F. Porter, Joor. Moiph, Tot 14, IMS. 

<5) ($)<£> 


body composed of melanin pigment, and then enter other corpuscles; 
spore-formation occurs every seventy-two hours or oftener, and is 
accompanied by a chill in the patient followed by a fever; if the blood 
is drawn into the intestine of a mosquito of the genus Anopheles certain 
of these spores produce flagellate individuals (microgametes), and others 
produce rounded spores (macrogametes) ; these two 
conjugate, and motile individuals (zygotes) are the 
result, which penetrate the intestinal mucous mem- 
brane and form large cysts on its outer surface; 
here they sporulate and develop finally into long, 
slender sporozoites which migrate into the body 
cavity and then into the salivary glands of tire Fi »-, 6 ?r- SSW 1 ?^** 

mosquito and are injected with the saliva into the T, n€ ? circles represent 
n ^ blood corpuscles Into 

blood of the next person the mosquito bites: wb JL c id h f /f^b* 6 b 1t 

3 species. grows until it mis the 

r corpuscle (E) and 

P. malariae (Laveran) (Pig. 69). The cause JJgj^ $"$5^ ffi 

of quartan malaria, in which the chill and fever the whole process ©c- 
* ' copying 72 noon. 

occur every seventy-two hours. 

P. vivax Grassi and Feletti. The cause of the tertian malaria in 
which the chill and fever occur every forty-eight hours. 

P. falciparum Welch. The cause of pernicious or autumnal malaria 
in which the chill and fever occur every twenty-four hours, or irregularly. 

2. Babesia Starcovici (Pyroaoma Smith 

Cl\ (¥\ £^l (S) an( * Kilbourne; Piroplasma Patton). An intra- 
s v-' ^— ^ ^^ corpuscular parasite of mammalian blood- 
corpuscles, without melanin pigment; trans- 
mission by the bite of ticks in whose intestine 
Sa'iD fleinf ^Th* s^cfc * ne P 8eu dosexual processes occur: many 

dee represent blood corpus- species. 
cles containing the parasite. * 

B. hominis (Manson) . The cause of Rocky 
Mountain spotted fever in man, the tick involved being Dermacentor 

B. bigemina (Smith and Kilb.) (Fig. 70). The cause of Texas fever 
m cattle, the tide involved being Margaropus (Boophilus) annulatus. 

Subclass 2. NEOSPORIDIA. 

Sporozoa which form sporocysts throughout life, the entire cell not 
being used in the formation of spores: 4 orders. 
Key to the orders of Neosporidia here described : 

«x In the organs of fishes and insects • 1. Myxospomdiida. 

a, In the muscle fibres of vertebrates 2. SABOOsroBmnp* 

feS f}T\ f7fi\ £T%S corpuscles, without melanin pigment; trans- 

Sporozoan parasites which occur in various organs of fishes, insects, 
and other animals; body amoeboid or spherical and multinuclear ; sporu- 
lation gives rise to sporoblasts in each of which one to several spores 
develop: 4 families, including some dangerous parasites, one of which 
is Glugea bombysis, the silk-worm parasite, which in thirteen yean 
previous to 1867 caused a loss in France of one billion francs. 


Parasites of fishes rarely found in the amceboid form, but usually 
as cysts filled with spores in which are vacuoles which are stained 
reddish brown by iodine: 3 genera. 

Htzoboldb Butschli. Spores ovoid or elliptical : about 40 species. 

M. lintoni Gurley. In all the tissues of Cyprinodon variegattu. 


Sporosoan parasites in the muscle fibres of 
vertebrates; body elongate forming cysts with a 
double membrane, in which are spores: 1 genus. 

2. Saboootbtib Lankester. Elongated Sporo- 
toa living in the muscle fibres of the pig, sheep, rat, 
and other animals : about a dozen species. 

8. miescheriana (Kiihn) (Fig. 71). Length of 
cyst 3 mm. : in the pig. 

> Class 4. INFUSORIA, f 

The Infusoria are distinguished by their defi- 
nite body form, the outer surface of the body being 
bounded by a firm outicula, and by the possession 
of cilia. These cilia are short hair-like pro- 
jections of the ectosarc through the eutieula, 
KUr. ti — BarcuuytUa and in the various species may appear as rapidly 

tDoflein). A. a <?«; vibrating locomotory organs, or may be united 
, a piece of pork', , , , , 

containing cysts, to form tentacles, spines, membranes, or suck' 

ing tubes. The ectosarc is often highly specialized. 

In many forms it contains large numbers of defensive organs 

called trichocysts, which are minute rods lying perpendicular to 

' "The Hyxoaporldla or Paorosperma Of Fishes and the Epidemics Produced by 
Them," by H. Ii. Gurley, Bull. U. 8. Flab. Com., Vol. II, 1803. 

t See "A Manual of the Infusoria," by W. S. Kent, 1881. "A Preliminary Contri- 
bution towards a History of the Fresh-water Infusoria of toe Doited State*," by 
A. C. Stoke*, Jour. Trenton Nat Btat Boc, Vol. 1, p. 71, 188S. 


the surface which may be shot out into the water. In a few 
forms (VorticeUa) nettle organs are present The ectosarc often con- 
tains muscle ridges called myonemes, which appear as parallel longi- 
tudinal or spiral lines, and in a few cases (Stentor) striated muscle 
fibrillae are present. The entosarc is more fluid than the ectosarc and 
is granular and contains a variety of specialized structures. Chief of 
these are the nuclei, of which two kinds are present, the micronucleus 
and the macronucleus. The latter is of large size and often branched 
or irregular in shape, and is supposed to be vegetative in function. 
The very much smaller micronucleus, of which more than one may be 
present, lies alongside the macronucleus and is chiefly concerned with 
reproduction and conjugation. The entosarc also contains one or more 
contractile vacuoles and food vacuoles. The former have a definite 
position in the body and serve to eliminate the water taken in with the 
food vacuoles together with the excretory wastes. The food vacuoles 
are globules of water which are taken into the entosarc together with 
the food. 

The food of Infusoria consists of organic particles of all sorts: 
some live principally on animal food, some on plant food, many are 
scavengers, and a few are parasitic. In all, with the exception of 
certain parasitic forms, mouth and gullet are present: an oral groove 
may lead to the mouth. The anus is usually a temporary opening. 

The Infusoria reproduce by division, the animal in most cases 
dividing into two equal parts. In some forms division takes the form 
of budding. Conjugation takes place in all Infusoria. The two conju- 
gating individuals fuse, in most cases temporarily by the ectosarc of 
the mouth region, and an interchange of micronuclear substance takes 
place. The macronucleus disintegrates in each animal while the micro- 
nucleus divides several times. The products of these divisions disin- 
tegrate, with the exception of a single one, which divides again. Of 
the two micronuclei thus obtained in each of the conjugating individ- 
uals, one migrates across to the other individual and fuses with the 
micronucleus remaining there. This fusion micronucleus then divides 
and a portion of it enlarges to form a new macronucleus. Where more 
than one micronucleus is present, it is probable that this process goes 
on with all of them. All Infusoria encyst themselves at certain times, 
in which condition they may be carried by the wind long distances. The 
Infusoria are found in both fresh and salt water. The name originated 
with Ledermuller in 1763 and was at first applied to all minute organ- 
isms which may appear in infusions. Only in modern times has its 
use been confined to protozoans. The class contains about 1,200 species 
grouped in 2 subclasses. 


Key to the subclasses of Infusoria: 

Ox Cilia present 1. Ciliata 

a, No cilia present in the adult, but long sucking tubes 2. Suotoria 

Subclass 1. CILIATA. 

Protozoa with cilia and usually with a definite mouth and gullet: 
4 orders with about 1,000 species, of which about 400 are marine. 
Key to the orders of Ciliata: 

0t Cilia usually, but not always, present on all parts of the body. 

6* Cilia all approximately of the same length 1. Holothichtda 

ft, Mouth surrounded by an adoral zone of large cilia 2. Heterotrichida 

a, Cilia present on only a part of the body. 

6i Cilia confined to the ventral side 3. Htfotbichida 

5* Cilia confined to one or more rings around the body 4. Perttbichida 


Protozoa in which the cilia are usually evenly distributed over the 
body, with a tendency to arrange themselves in straight lines, which 
have often a spiral arrangement; in the vicinity of the mouth the cilia 
are often longer than elsewhere and in a few forms are confined to this 
region; trichocysts almost always present: 10 families. 

Key to the families of Holotrichida here described : 

Oj Animals not parasitic. 
6 X Mouth closed except when taking in food, and without undulating membrane. 
Oj Mouth terminal or subterminal. 

d x Body usually oval or cylindrical 1. Enchelinidae 

d % Dorsal side arched ; forward end often neck-like 2. Tbachelinidae 

c, Body ovoid ; mouth in middle or posterior region 3. Chlamydodontidae 

6, Mouth always open and ventral with an undulating membrane around it or 
in the gullet. 
o l Oral groove absent or slightly developed. 

dx No equatorial zone of cilia 4. Chtlifebidae 

d t Broad equatorial cone of cilia 5. Urocehtridae 

c, Long oral groove present. 

dx No undulating membrane along oral groove 6. Paramechdae 

d t An undulating membrane along the oral groove 7. Pleuronemtdae 

a, Animals parasitic ; mouth absent 8. Opaunidae 


Usually oval Infusoria, sometimes with a long slender forward por- 
tion, with a terminal mouth by which large objects are swallowed, food 
not being introduced in currents, as the gullet is never ciliated: about 
18 genera; principally in fresh water, 


Key to the genera of Enchelinidae here described : 

Oj Cilia cover whole body. 
b x Body not covered with rectangular plates. 
Cx Body not elongate and contractile, 
da Gullet absent or short, 
e, Posterior bristle not present. 

fx Mouth terminal ; body ovoid 1. Holophbta 

/, Mouth subterminal ; body with slight neck 2. Enchklts 

a, Posterior bristle present 3. TJrotrioha 

d, Gullet long and lined with a membrane 4. Pbobodon 

c, Body elongate and contractile. 

d\ Body flask-shaped with contractile neck 5. Lacbyicakia 

d\ Body very long and contractile 7. Tbacheloceboa 

ft, Body covered with rectangular plates 6. Oolbpb 

a, Cilia confined to 1 or 2 girdles. 

&i Deep equatorial furrow present 8. MssoDnouic 

ft t No such furrow 0. DmnauM 

1. Holophbta Ehrenberg. Body striated, cylindrical or ovoid; 
ciliation uniform; no trichocysts; 6 species; in fresh and salt water. 

Fig. 72 Fig. 73 Fig. 74 

Fig. 72 — Bolophrya discolor (from Bronn). Fig. 73 — Bnchetys pupa (Conn). 

Fig. 74 — Urotrieha fareta (Conn). 

H. discolor Ehr. (Fig. 72). Body ovoid ; length .04 mm. : in standing 

2. Evghelys O. F. Miiller. Anterior end somewhat elongated and 
truncated with subterminal mouth: 5 species; in fresh and salt water. 

E. pupa Ehrenberg (Fig. 73). Body ovoid; length .08 mm.; color 
often greenish. 

3. Ubotbioha Claparede and Lachmann. Like Bolophrya, bat with 
a bristle at hinder end: 2 species; in fresh water. 

U. fareta CI. and Lach. (Fig. 74). Springs with its bristle; length 
.02 mm. 

4. Pbobodow Ehrenberg. Body ovate or ellipsoid, with a long 
gullet lined by a membrane: 8 species; in fresh water. 

P. grisens Clapar&de and Lachmann. Length .25 mm.: in standing 

6. Lacbyxabia Ehrenberg. Body flask-shaped, with a contractile 
neck and spiral striatums: 4 species; in fresh and salt water. 

Fig. 75 



L, olor (0. F. Miiller) (Fig. 75). Body extremely 
elastic, colorless or green; length without neck 3, mm.; 
neck may be much longer than body: in fresh water. 

L. lagonula Claparede and Lachmann. Body flask- 
shaped, with a short conical neck which has a crown 
of longer cilia; length up to .16 mm.: in decaying 
marine and fresh-water algae. 

6. Ooisn Nitzsch. Barrel-shaped, 
rigid, with an armor composed of rect- 
angular plates between which the cilia 
project: 3 species; in fresh water. 

0. hirtus Ehrenberg (Fig. 76). Gray 
or green; length .04 mm.: in swamps. 

7. Tbacbbxooeboa Ehrenberg. Body 

very long, slender, and contractile: ma- ^' 

. . . CofeM hlrtia 

rme; 1 species. (Conn). 

T. phoeni copter eh Cohn (Fig. 77). 
Length up to 1.7 mm.; with a four-sided mouth, which may not be 
seen : Woods Hole. 

8. Mebodinttoi Stein. Body globular or conical, with a deep furrow 
around the middle from which spring one or more rows of cirri; 4 con- 
tractile tentacles in the mouth: 3 species; in fresh and salt 

M. daetum Calkins (Fig. 78). Cirri projecting forward 
number about 30: marine; Woods Hole. 

0. Didiwiuk Stein. Body cylindrical, with 1 or 2 
girdles of cilia and with a horseshoe-shaped macronucleus ; 
forward end a projecting cone with the mouth at the tip: 
2 species; in fresh water. 

D. nasntam* (0. F. Miiller) (Fig. 70). Length.:! mm: 
feeds on Paramecium and 
other large infusorians. 

Family 2. 


Dorsal side of body 

arched ; mouth terminal 

suhterminal, usually 


rflpMMTM at the end of 
neck: 6 genera. 

Fig. 78 - 


Fla. 76 

m cinvtvm 

n — DUinttm 

, bj 8. 0. Matt, Biol. Salt, 


Key to the genera of Trachelinidae here described : 

Ox Distinct neck region. 
&t Month runs the length of the neck. 

c, Entire body uniformly ciliated 1. Amfhileftub 

c, Ventral surface only ciliated 2. Lionotub 

b, Month at base of neck, which is very long 4. Deleptus 

a, No distinct neck region 3. Loxophtllum 

1. Axphtxbptto Ehrenberg. Body often curved, elongate, flattened, 
with a sharp neck-like forward end; no gullet: 3 species; in fresh and 
salt water. 

A. gntta Claparede (Fig. 80). Macronucleus double; length .08 mm. 

Fig. 81 

Fig. 80 — AmpMleptua gvtta 
(Conn). Fig. 81 — Lionotu* Jwt- 
ciola (Calkins). Fig. 82 — Lotto- 
phyllum rostratum (Conn). 


Fig. 80 

Fig. 82 

2. Lionottxs Wrzesniowski. Body elongate, tapering to both ends, 
with a large hump; usually two macronuclei; flattened side only ciliated; 
anterior end neck-like: 6 species; in fresh and salt water. 

L. wrzesniowskii Kent. Length .18 mm. : in fresh water. 

L. fasdola (Ehrenberg) (Fig. 81). Body ellipsoid, hinder end 
conical; length up to .6 mm.: in fresh and salt water; .Woods Hole; Cold 
Spring Harbor. 

3. Loxofhyixum Dujardin. Body flat, with a broad hyaline border; 
anterior projection slight, turned to the right; trichocysts often in 
papilla-like groups; nucleus often bead-like: in standing water; 4 
species; in fresh and salt water. 

L. rostratum Cohn (Fig. 82). Body elongate; 
length .15 mm.: in fresh water. 

L. setigerum Quennerstedt. Body broad; 1 Fig. 83 — Diieptus anser 
mm. long: in salt water. 

4. Dilepttjb Dujardin. Body large, elongate, with a long contractile 
neck, at the base of which is the mouth; numerous contractile vacuoles; 
nucleus often bead-like: 2 species; in fresh and salt water. 

D. anger (0. F. Miiller) (Fig. 83). Body striated; length up to 
1.5 mm. : among algae in fresh water. 

Ovoid or kidney-shaped Infusoria with the mouth usually some dis- 
tance from anterior end; gullet specially modified to swallow food of 
large size: about 11 genera. 

1. Nasbuta Ehrenberg. Body ovate or cylindrical; mouth between 
middle and anterior end; gullet armed with rods or with a membrane: 
8 species; in fresh and salt water. 

N. ornata Ehr. Body nearly circular, usually with brightly colored 
spots; gullet with rods; length 2 mm.: in fresh water. 

N. microstoma Cohn (Fig. 84). Body nearly circular, with brightly 
colored spots; gullet with a membranous lining; length .05 mm.: 
marine; Woods Hole. 

2. Oeoooov Ehrenberg. Body flattened, with convex dorsal side; 

Tig. 84 Fig. 86 Fig. 86 

Flff. 8*— Xatsula maerottema (Calkin*). Flg.85 — Chuodnn cveuUvlv$ <Calklna). 
Fig. 86 — Frontonia Itnuita (Calkins). 

mouth at or in front of middle of body; gullet armed with rods: 
6 species; in fresh and salt water. 

0. cucuUnlua (0. F. Muller) (Fig. 85). Length .1 mm. or less; 
body ovoid; forward end bent to the left: in fresh and salt water. 

Family 4. CHILI FEE ID AE. 

Mouth never behind the middle and always open, with an undulating 
membrane on the edge of it or in the slightly developed gullet: 
9 genera. 

Key to the genera of Chili feridae here described : 

a. Long ventral furrow leading back from the mouth 1. FBOHToltlA 

0] No such furrow. 

6, Caudal bristle present 3- Ubonbma 

b, No bristle. 

o, Bod; oval, symmetrical 2. Coi.pidiuM 

e. Body rounded dorsallv, straight Tent rally 4. Colpoda 

1. Fkomtohu Ehrenberg. Body large, ellipsoid or elongate and 
contractile and colorless, or green or brown, with mouth near forward 


end and an undulating membrane in the gullet: 3 species; in fresh 
and salt water. 

F. lancas Ehr. (Fig. 86). Body brown or black in color; length 
.3 mm. or more; a furrow extends back from the mouth: in fresh and 
salt water; Woods Hole. 

2. CoLHDnm Stein. Body oval, the ventral side being incurred 
and the forward end smaller than the hinder; mouth central: 2 species; 
in fresh and salt water. 

0. colpoda (Ehrenberg) (Fig. 87). Length .045 mm. or more: in 
fresh and salt water; common in infusions; Woods Hole. 

3. Ueosema Dujardin. Body minute and oval, with a long bristle 
at the hinder end; mouth near middle surrounded by membranes: 6 
species; in fresh and salt water. 

Fig. 87 Fig. 88 Fl*. 88 

Flff.67 — Volpidlum colpoda (Calklni). Pig. 88 — Vronema marinum (Calklni). 

tig. 8(t — Colpoda cucullwi (Codd). 

U. marinam Duj. (Fig. 88). Length .05 nun.: in fresh and salt 
water; in decaying vegetation; marine; Woods Hole. 

4. Colpoda O. F. Miiller. Body laterally compressed, with rounded 
dorsal and straight ventral surface; mouth toward forward end, sur- 
rounded by long cilia: several species; in fresh water, especially in hay 

0. cncnUiu Miil. (Fig. 89). Body ellipsoidal; length .1 mm.: in 
fresh water; very common. 

Body barrel-shaped; month near the middle; a broad girdle of 
longer cilia around the body: 1 genus. 

UsoonrXBim Nitzsch. Characters as above : 1 species ; in fresh and 
salt water. 

U. turbo (0. F. Muller) (Fig. 90). Length .06 mm.; swims with a 
whirling motion. 

Famii.y 6. P ATtAWwnmAii: . 

Body elongate, with a long, deep, oral groove leading to the mouth 
which is in the middle or hinder part of the body: 1 genus; common in 
infusions and decaying organic matter. 



Paramecium* O. F. Miiller. Slipper-animalcules. Characters as 
above; trichocysts distinct; two contractile vacuoles: 4 species; in fresh 
and salt water. 

P. aurelia Miil. (Fig. 91). Forward end rounded; hinder end bluntly 
pointed; length .15 mm.; 2 micronuclei : in fresh and salt water; common. 

P. caudatum Ehrenberg (Fig. 92). Like P. aurelia, but somewhat 
larger and more pointed behind and with 1 micronucleus : in fresh 
water; commoner than the preceding. 

Fig. 90 Fig. 01 Fig. 92 

Fig. 90 — Urocentrum turbo (Conn). Fig. 91 and Fig. 92 — Paramecium aurelia 

and P. caudatum in outline (George T. Hargitt). 

P. bursaria Ehr. Body wide, rounded, and obliquely truncate for- 
ward and pointed or rounded behind; usually bright green from the 
numerous green algae (zoochlorellae) in the ectosarc; length .12 mm.: 
in fresh water. 


Body oval or ellipsoidal, with a long, deep oral groove leading to 
the mouth in hinder part of body; along the edge of this groove is a 
large undulating membrane : 5 genera. 

Key to the genera of Pleuronemidae here described : 

Ot No caudal bristle. 

&! Hinder end acute 1. Lembadion 

ft, Hinder end rounded 2. Plbubonema 

o, Caudal bristle present 3. Lembus 

1. Lembadion Perty. Body oval, rigid, posterior end acute: 1 

L. bullinum Perty (Fig. 93). Length .05 mm.: in fresh water. 

2. Pleurovema Dujardin. Body rigid, oval, and flattened; oral 
groove takes in a large part of the ventral surface and with a high, undu- 
lating membrane; cilia very long: 2 species; in fresh and salt water. 

P. chrysalis (Ehrenberg) (Fig. 94). Moves by springs and by swim- 
ming; length .04 mm.: in fresh and salt water; in decaying vegetation. 

• Bee "Races of Paramecium/' by H. 8. Jennings and O. T. Hargitt, Jour. Morph„ 
Vol. 21, p. 495, 1910. "Two Thousand Generations of Paramecium," by L L. 
Woodruff, Arch. f. Prot. Vol. 21, p. 263, 191 L. "Paramecium aurelia and P. 
caudatum," by same, Jour. Morpb., Vol. 22, 1911. 

3. IiKKsvb Cohn. Body elongate, with a long caudal bristle; mouth 
in the middle with the oral groove leading to it from the forward end; 
in decaying plants; 3 species; marine. 

Fig. M Fig. 91 Fig. 95 

ftnllinum (Conn). Pig. 94 — Plttironrma 
Fig. BB — Lembus injusionum (L'alklna). 

Fig. 93 — LembaAion bnllinum (Conn). Pig. 94 — Plttironrma chryiatlt (Calklnl). 

L. infusionum Calkins (Fig. 95). Body lancet-shaped, with a taper- 
ing anterior extremity ; a row of contractile vacuoles extends from the 
hinder end forward; length .07 mm.: Woods Hole. 

Family 8. OPALINIDAE. 

Month absent; body oval or elongate; 6 genera, parasitic in the 
Anura and in worms and mollusks. 

1. PAU ha* Purkinje and Valentin. Elliptical Infusoria living 
parasitic in the rectum of frogs and toads; 13 species. 

O. Tuuumm Pur. and Val. (Fig. 96). Body flattened; 
many contractile vacuoles; length .6 mm.: in frogs and 

2. AvonOFKBTA Stein. Body elongate: in the di- 
gestive tract of marine annelids and on the gills of 
crustaceans; occasionally free-swimming. 

A. branchlarnm St. Length .1 mm.; body flask- ojwhbo 

shaped; Woods Hole; free-swimming. fflofcSf. 


Body with uniform ciliation and an adoral zone along the oral 
groove consisting of cilia fused together to form membrane lies : 7 families. 

Key to the families of Heterotrichida here described : 
a, Body not in a cap. 
6, Body not with a crown of long cirri. 
c, Bod j not funnel or trum pet-aba ped. 

rf, Body elongated 1. Plaoiotokidai 

d. Body usually oval with a triangular oral groove 2. Burhaeiloak 

c, Body funnel or trumpet-shaped 3. Stkntobtdae 

b, Body with a crown of long cirri 4. HAtTERrroAB 

a. Body in a cup 5- Tintthnidae 

■ See "OpiUna," by H. M. Metcair, Arch. f. Prot., Vol. 13, p. IBB, 11)09. 




The oral groove extends from the forward end of the month, near 
the middle of the body; adoral zone along the left side of the groove; 
body elongate: 6 genera. 

Key to the genera of Plagiotomidae here described: 

a% Oral groove spiral 1. Meiofto 

a, Oral groove straight. 

&! Forward end acute and turned to the left 2. Blephabisma 

b, Body straight and worm-like 3. Spirobtomuic 

1. Metoptts Claparede and Lachmann. Body cylin- 
drical; oral groove extends spirally across the forward 
two-thirds of body; contractile vacuole at hinder end: 
2 species ; in fresh and salt water. 

M. sigmoidea (O. F. Miiller) (Fig. 97). 
Length .13 mm.; body very contractile: in 
fresh water. 

2. Blefhabxsxa Perty. Forward end 
acute and turned to the left; hinder end 
rounded : several species ; in fresh water. 

B. midnlans Stein (Fig. 98). Length 
.37 mm. ; color red : in fresh water. 

S. SpiEOSTomm Ehrenberg. Body long, 
cylindrical, and worm-like, very contractile, with dis- 
tinct spiral striations; nucleus bead-like; oral groove in 

about first third of body; contractile 
vacuole at hinder end: 2 species; in fresh 
and salt water. 

8. teres Claparede and Lachmann 
(Fig. 99). Length .4 mm.; body tapers 
slightly at both ends; nucleus sometimes 

8. ambiguum (Bory de Vincent). Body 
1 mm. long or more, and not tapering. 

Fig. 07 




Fig. 08 

Fig. 00 







Family 2. BUE8AEIIDAE. 

Body usually oval and flattened, the oral groove being a triangular 
sunken area ending in the mouth; adoral zone on left edge of groove: 
5 genera. 

Key to the genera of Bursariidae here described : 

Ox Animals parasitic 2. Balantidium 

a, Animals not parasitic. 

&! Body very broad 1. Bubsabia 

b, Body cylindrical 3. Condylostoma 


1. Bubsuu 0. P. Wilier. Body large, purse-shaped, obliquely 
truncate in front; nucleus long, ribbon-like: 1 species; in fresh water. 

B. truncatell* Miil. (Fig. 100). Length 1 mm. 
and more: often between fallen leaves in the 

2. BaM JmmrM Stein. Body spindle-ahaped, 
with the oral groove at the apex : 4 species, para- 
sitic in mammals, amphibians, and worms. 

B. coli St. (Fig. 101). Length 02 mm.: in 
the large intestine of the pig and man, causing 

B. eatoxoon (Ehrenberg). Length .2 mm.: sis. 100 

in the large intestine of frogs, toads, and Bunoria truncauito 
salamanders. it-onnj. 

3. Comdylobtoma Dujardin. Body rounded or cylindrical, tapering 
anteriorly with obliquely truncate forward end; nucleus bead-like: 2 
species, in fresh and salt water. 

O. patens (O. F. Miiller) (Fig. 102). Length .4 nun.; width .10 
mm.: fresh and salt water. 

Ft*. 101 Fig. 102 

Fig- 101 — llalantltHum ooK (Dofleln). __,. .._.. 

Pig- 103 — Stcntor Otmteu* ( 

Faictlt 3. STENTOBIDAE. 

Body the shape of an elongated funnel and very contractile, the 
small end of which can be attached; large end truncate, the adoral zone 
passing around the edge; nucleus usually beaded: 2 genera; in fresh 

SxxMTom* Oken. Fixed or free-swimming; when swimming body 
is contracted and ovate : 8 species ; in fresh water. 

S. ccerulena Ehrenberg (Fig. 103). Body blue; length .25 mm. 

• See "Selection of Food Id Stentor ccernlens (EDr,)," tij A. A. SchaeSer, Jour. 
B*p. TooL. Vol. 8. p. 889, 1810. 


8. polymorph!! (0. F. Miiller). Body usually green from the pres- 
ence of algae (zoochloreUae) but sometimes colorless; length 1 mm.: 
sometimes very abundant on water plants. 

8. raseli Ehr. Body colorless; nucleus ribbon-shaped; often 
attached by a short ease; length 1 mm. 

FiMttY 4. F * T. T I-niTIT) A V. . 

Body spherical or ovoid, often with long bristles and a few cilia 
scattered over the body; animal moves by springing: 2 genera. 

1. Halthua. Dujardin. Body small, spherical, 
with anterior adoral ciliated zone, and usually body 
bristles: 2 species; in fresh water. 

H. grandinella (0. F. Hiiller) (Fig. 104). 
Length .04 nun. 

2. STBOXBionm Claparede and Lachmann. Like 
Fig. 104— ffalterttt Halteria, but without the bristles: 6 species; in 

grvnitolU, (BronD). fresh and ^ waUr 

S. caudatum Fromentel. Caudal appendage present; length .035 
mm.: in fresh and salt water. 

Body attached by a stalk to a cup: 5 genera. 

1. Tnrrmrozui Stein. Animal in a chitinous 
cup on which are embedded sand granules; anterior 
end has two circles of cilia: numerous species; 

T. beroldea St. (Fig. 105). Cup thimble-sbaped ; 
length .05 nun. : Woods Hole. 

T. d&vidofll Daday. Cnp elongate with a long 
spine; length 23 nun. 
Fig. 105 ~ rinHn- 2. TrHTiH(rnB Ehrenberg. Like Tintinnopsia 

(Caikins). r ' ° except that no sand grains are imbedded in the cnp: 
numerous species; in fresh and salt water. 
T. amphora Claparede and Lachmann. Length .1 mm.; cup elon- 
gate: marine; Cold Spring Harbor. 


Body flattened and with cilia, spines, cirri, and membranellea 
confined to the ventral surface; dorsal surface may have bristles: 3 



Key to the families of Hypotrichida here described : 

Ot Body usually elongate and broad, with ventral cilia 1. Oxytbichidax 

a, Body more or less circular with very long bristles and cilia usually absent 



Body somewhat elongate with arched dorsal and flat ventral side, 
the latter with cilia, bristles, etc.; month near the middle witfi an oral 
groove running backwards: 21 genera; in fresh and salt water. 

Key to the genera of Oxytrichidae here described : 

Ox Several median longitudinal rows of continuous cilia. 
&t Five or more rows of cilia. 

Ct Mostly fresh-water animals 1. Ubosttla 

c, Marine animals 2. Bpiclintes 

b t Less than 5 rows of cilia, 
c, Neither anterior nor anal bristles; body acute anteriorly. .3. Stichotbicha 
c, Such bristles present ; body usually broad. 

d\ Animals mostly marine 4. Amphibia 

d^ Animals mostly in fresh water. 
«, Two median rows of cilia. 

f x Three anterior and no anal bristles 5. Uboleptub 

f t No anterior bristles ; anal bristles present 7. Holosticha 

e, Three or 4 rows, body broad and rectangular 6. Onychodbomus 

a, No median rows of continuous cilia ; but marginal rows present. 

6j No caudal bristles 8. Oxttbicha 

5, Three long caudal bristles 0. Sttlontchia 

1. TJbostyla Ehrenberg. Body flexible, elliptical, 
with longitudinal striations and rows of cilia; oral 
groove at forward end; 5 to 12 long anal bristles in 
an oblique row, and 3 or more anterior bristles: 6 
species; in fresh and salt water. 

U. trichota (Stokes) (Fig. 106). Length .3 mm.; 
5 anal and about 20 anterior bristles: in fresh water. 

2. Epiolikte8 Stein. Body flexible, elongate, the 
forward half being ovate, the hinder end slender and 
cylindrical; several longitudinal rows of cilia: 1 
species; marine. 

E. radiosa Quenner- 
stedt (Fig. 107). Length 

.046 mm.; 5 large bristles at Fig. iw—Epiciinte* radiota 
forward end: Woods Hole. (Calkins). 

3. Stiokotxioha Perty. Body cylindrical and very contractile, 
with acute forward end; oral groove extending back to middle of 
body; 2 or 3 rows of cilia; color often green: 4 species; in fresh and 
salt water. 

8. secunda Perty (Fig. 108). Length 2 mm.: in fresh water. 

Fig. 106 
Urottyla trichota 




i. Amphibia Sterki. Body elongate and cylindrical and contractile, 
with rounded ends and often tinged red or yellow; several anterior 
bristles and 5 to 10 anal bristles; oral groove extends back to middle 
of body: 7 species; in fresh and salt water. 

A. kesaleri (Wrzesniowski) (Fig. 109). Body wider anteriorly; 
length .13 nun.: marine; Woods Hole. 

G. tFaoLXPTtra Ehrenberg. Body cylindrical or flattened and slen- 
der with rounded anterior and acute posterior ends; 3 anterior and 
no anal bristles; oral groove short; 2 continuous rows of median cilia: 
5 species; in fresh and salt water. 

TJ. longicandatus Stokes (Fig. 110). Length .2 
mm. : in fresh water. 

6. OHTOHODBOHVa Stein. Body broad, somewhat 
rectangular; 3 or 4 rows of ventral cilia; one row of 
large cilia along the oral groove: 1 species. 

0. grandla St. (Fig. 111). Length .35 mm.; width 
.12 mm.: in fresh water; slow of movement. 

7. Holostioha Wrzesniowski. Like Oxytricha 
except that there are 2 rows of median cilia and no 
anterior bristles. 

H. vemalis Stokes. Body elliptical, rounded at 
n i *_ both ends; length .07 mm.: in fresh water. 

prantti* 8. OxYTBiCKA Ehrenberg. Body elliptical, with a 

row of cilia along each lateral margin and a mid- 
ventral group of bristles, consisting of about 8 bristles along the oral 
groove, about 5 in middle of the body, and about 5 anal bristles: several 
species; in fresh and salt water. 

0. peDlonalla, (O. F. Muller). Body elongate; length .09 mm.: in 
fresh water. 


0. bifaria Stokes (Fig. 112). Body broad; length .2 mm.; bristles 
in a single line: in fresh water. 

9. Sttlohtokia Ehrenberg. Body elliptical, 
rigid; oral groove triangular or serai circular, reach- 
ing middle of body; cilia and bristles as in Oxytricha; 
usually 3 long caudal bristles present: 
6 species; in fresh and salt water; very 
common, the animals often moving by 
quick jerks. 

S. pustnlata Ehr. Body broad; 
length .25 mm.; width J. mm.; in 

8. mytllufl (0. F. Muller) (Fig. 
Pl^ 112 113). Body broadest in front of 
Oftrleha middle; length .3 mm.: in fresh Fig. 118 

(Conn). water. mytttuiljtoaeiB). 

Family 2. BUPLOTTDAE. 
Cilia very little developed or absent ; large bristles and spines char- 
acterize the ventral surface; nucleus ribbon-shaped; body round or oval: 
5 genera; mostly marine. 

Key to the genera of Euplotidae here described: 
a, No posterior hook-like projection at side of body. 
b. Anterior bristles present. 

c, About 9 anterior bristles 1. Eopldtks 

e, About 6 anterior bristles 2. Diophbtb 

t>, No anterior bristles 3. Ubontchia 

a. Posterior hook-like projection at side of body 4. Abfidisca 

1. Euplotes Ehrenberg. Body oval 
or roimd, either green or colorless; mouth 
in the hinder half of body, a long arched 
oral groove joining it with the front end 
of the body ; about 9 large bristles oppo- 
site the groove and a similar number of 
anal bristles: 5 species; in fresh and salt 

Fig. 114 Fig. 11B 

B. Charon (O. F. Muller) (Fig. 114). p, in_^ BP , 0( .. oJW ™, 

Length .045 mm.: in fresh and salt £?*^ M ™< c J&r ) ? lop ' ,n '' 


2. PlOPHSYg Dojardin. Like Euplotes except that about 6 anterior 

and 8 anal bristles, all very long and thick, are present; movement rapid 

and continuous, not by jumps: 2 species; marine. 

D. appradicnlatus Stein (Fig. 115). Length .05 nun.: Woods Hole. 


3. Ubostohu Stein. Like Euplotes except that no anterior and 
about 10 great anal bristles are present; movement rapid, with frequent 
jumps: 2 species; marine. 

U. setigera Calkins (Fig. 116). Length .04 mm.: 
common at Woods Hole. 

4. Aspidisoa Ehrenberg. 
Body oval with a short oral 
groove in the middle of the 
body and a short posterior 
projection at the side of 
body; abont 8 thick, anterior, 
and 6, or more, anal bristles: 
in fresh and salt water. 
m ^ A. hexaris Quennerstedt 

(Fig. 117). Length .07 mm.; 
6 anal bristles: Woods Hole. 


Cylindrical or cup-shaped infusoriane in which the body is without 
cilia except those forming the adoral zone at the oral groove, and in 
a few cases a zone at the hinder end ; most of them are sessile : 3 families. 

Key to the families of Perilrichida here described : 

a, Body attached by a broad sucking disc 1. Lichnophortdae 

a, Body usually attached by a slender stalk 2. Voeticeludae 


Forward part of the body with an oval oral groove; the hinder 
part stalk-like and broadened at the end to form a sucking disc 
piovided with a rin«r of cilia, by 
which the animal fixes itself: 1 
genus; marine; usually parasitic 
on mollusks. 

LlOHMOPKOftA Claparede. 
Characters given above. 

L. macfarlandi Stevens (Fig. ™*- 118 — L ^^^ «eo/«rtaa* 

118). Length .08 mm.; the animal 

moves about on its pedal disc: Woods Hole, on the egg capsules of 
Crepidula and on annelids. 


Body cup-shaped and cylindrical and, with one or two exceptions, 
attached by a stalk at the hinder end; oral groove circular, around the 


edge of the cup; body very contractile; nB Jn w h frequently colonial; 
16 genera. 

Key to the genera of Vorticellidae here described : 
a. Animals not senile and without a atalft ; parasites or commensals on Hydra 

and other animals 1. Thichodma 

a, Animals sessile and stalked and not parasitic, although often attached to other 
6, Bod? not enclosed In a cap. 
c, Stalk long or short and not branched ; animals solitary. 

d. Stalk lone and coDtractile 2. Vobtiokua 

rf, Stalk short and not contractile. 
e, Oral disc acts like a cover {operculum) which may close the opening of 

the cup 8. Ptxuhttv 

e, No each cover 4. Rhabdostyt,* 

o, Stalk branched ; animals colonial, 
a\ Stalk contractile. 
&i Each individual of the colony can contract independently. 

5. Cahchesium 

e, The colony contracts as a whole 6. ZooTHAianux 

i. Stalk not retractile, bnt rigid. 

e, No operculam 7. Episttlis 

e, Operculum present 8. Opebouubia 

6, Body enclosed in a transparent cup 9. Cothuruta 

1. Teioboddta Ehrenberg. Body short, cylindrical or disc-shaped 
with a ring of cilia around the circular flat base; oral end also flat; 
parasites or commensals on Hydra, planarians, and other small animals, 
also en the gills of fishes, attaching itself by the sucker-like base or moving 
over the surface of the body; sometimes entopara- 

sitie in the urinary bladder or intestine of fish or 
amphibians; several species, 

T. pcdicnlns Ehr. (Fig. 119). Length .08 
mm. : often common on Hydra. 

2. Vostiozixa L. Body more or less bell- 
shaped with the oral groove extending inwards Fig. lis — Trlahoitna 
from the rim and with a long stalk; nucleus horse- 
shoe-shaped; colorless or green or blue: many species; in salt and fresh 
water, on plants and animals. 

V. nebnlifera Ehrenberg (Fig. 120). Body campanulate, some- 
times green in color, .07 mm. long with a stalk 4 times as long : in clear 

V. campanula Ehr. The largest VorticeUa, with a body .2 mm. 
long or less, bluish in color, and a stalk several times as long, not 
simulated: in fresh water, often in clumps on water plants. 

V. convall&ri* L. Body annotated, .1 mm. long, with a long stalk: 
in infusions. This animal is interesting because it was the first micro- 
scopic animal discovered by Leeuwenhoek. who first saw it in April, 1675. 


V. patellina 0. F. Miiller (Fig. 121). Body not annulated, with a 
very wide oral end; length .05 mm. : in fresh and saltwater; Woods Hole. 

V. marina Greef. 
Body annulated, .035 
nun. long: marine; 
Woods Hole. 

3. Prannm Kent. 
Stalk short, and not 
contractile; body elon- 
gate and elliptical, with 
a small oral end; oral 
cilia on a disc called 
the operculum which can 

si*, iko ng. i2i cl0Be down ]ike * Ud - 

P. ramoaa Stokes. 
Length .15 mm.: in 
fresh water. 

4. Rhabdosttla Kent. Like Vorticella but with a short and non- 
contractile stalk; body bell-shaped or elongate, 

with small oral end. 

R. brevipea (Claparide and Lachmann). 
Length J mm. : in fresh water. 

5. OAHCHBsruH Ehrenberg. Richly branched 
colonies which form visible grayish masses on 
water plants and often animals; each individual 
can contract independently: several species; in 
fresh water. 

0. polyuinum (L.) (Fig. 122). Body broad 
and funnel-shaped and about J mm. long: com- 
mon in fresh and salt water. 

6. ZoOTxaiomnc Ehrenberg. Like Carche- 
sium, except that the colony contracts as a whole: 
several species, in fresh and salt water. 

Z. arbuscula Ehr. Body more or less cyl- 
indrical; length .05 mm.: on water plants in 
fresh water. 

7. Bpmttlm Ehrenberg. Like Rhabdottyla, 

bnt colonial; whole colony rigid: numerous spe- carchnium paiupmvm 
cies; in fresh and salt water, often on small (DooeUi). 


E. flavicans Ehr. (Fig. 123). Body bell-shaped, .1 mm. long: in 
fresh water. 


8. Opxsouijuua Ehrenberg. Like Pyxidium, but colonial; whole 
colony rigid: 8 species; in fresh water. 

0. articnlata Ehr. Body spindle- 
shaped, truncate at lower end, and .05 mm. 
long: on water beetles. 

9. Oothukmia Ehren- 
berg. Body elongate and 
enclosed in a colorless or 
brownish cap, at the bot- 
tom of which it is at- 
tached and into which it 
ean retract; cup also at- 
tached either directly or 
by a short stalk: namer- ~j* 

Fig. 123— BMttyKi Aatnomu oas species; in fresh and " Yatuna 
(Conn). ,. . (Calklni). 

salt water. 

0. crystallina Ehr. (Pig. 124). Length of cup .07 to 2 mm.: in 
fresh and salt water; Woods Hole. 

Subclass 2. SUCTORIA. 

Usually sessile Infusoria which have no cilia as adults but are pro- 
vided with long hollow tentacles adapted for sucking or piercing; they 
attach the tentacles to other Infusoria and suck them out; some are 
entoparasites in Infusoria : 8 families with about 200 species. 
Key to the families of Suctoria here described: 

a. Body globular, without a cup 1. PoDOFHBimua 

a, Body not globular. 

b. Body usually In a cup at end of a slender stalk 2. Acinetidab 

6, Body without cap or stalk ; tentacles knobbed 3. Dendbosoiodak 


Body globular and not in a cup; stalked or 
not, and with tentacles of different kinds, some 
knobbed and some acute: 5 genera. 

1. Sfksbofksta Claparede and Lacbmann. 
Body spherical or ovoid and without stalk, with 
knobbed tentacles radiating from all aides: free- 
living in swamps and infusions or entoparasites Fig. 12B — SpSwo- 

..... phrya magna. 

m Stentor, Paramecium, and other ciliates; 4 (Conn). 


8. magna Hanpas (Fig. 125). Diameter .06 mm.: among water 


2. POBOFHKTA Ehrenberg. Body spherical or ovoid and attached 
by a stalk; tentacles knobbed and radiating in all directions, either in 
groups or not : several species ; in fresh and salt water. 

P. gracilis Calkins (Fig. 126). Diameter of body 
.008 mm. ; stalk very long, measuring .04 mm. : in salt 
water; Woods Hole. 

3. Epkzlota Wright. Body more or lesa spherical, 
with a stalk; tentacles of two kinds, being either 
pointed and used for piercing, or short and cylindrical 
and used for sucking: 8 species; marine. 

E. coronaU Wr. (Fig. 127). Diameter of body 
.00 to 2 mm.; stalk three times as long, and thickest 
at the body: common at Woods Hole on campanula- 
rians, hydroids, etc. 

Family 8. ACINETIDAB. 

Body usually in a cup and usually stalked; ten- 
tacles knobbed; reproduction by endogenous budding, 
the spores being ciliated: 4 genera, 
n*. 1M 1. Aornii Ehrenberg. Body in a cap with a 

PadspAnw 0ro- stalk: several species; in fresh and salt water. 

A. divisa Fraipont (Fig. 128). Body .027 mm. 
long and does not fill the cup; tentacles long; length of stalk .1 mm.: 
a Bryozoa at Woods Hole. 

A. tnbexoa* Ehr. (Fig. 126). Cup very delicate and often difficult 
to see; tentacles in usually two groups; color yellow; length of body .33 
mm. : at Woods Hole, in salt water. 


2. Toxopheta Biitschli. Body not in a cup but at the end of a 
stalk: several species; in fresh and salt water. 

T. qoadrlpartita (Claparede and Laohmann). Body .1 nun. long: in 
fresh water. 


Body without oup or stalk; tentacles 
knobbed and arranged in groups; reproduction 
as in Adneta: 3 genera. 

1. Tkichophhya Claparede and laohmann. 
Body irregular in shape and spread out; fre- 
quently parasitic: in fresh and salt water. 

T. lalpanun Entz. On the branchial bars 
of Molgula: at Woods Hole; often common. 

2. DutDkosoiu Ehrenberg. Colonial ani- 
mals on long and branching stalks which spring 
front a creeping base: 1 species. 

D. radians Ehr. (Fig. 130). Colony up to 2 mm. high: 



The ecelenterates are radially symmetrical animals which possess 
bat a single internal cavity and no ctelom (Fig. 131). This cavity is a 
simple space in a more or leas cylindrical body in the lowest ccelenter- 
ates, but in the larger ones it is often extensively branched. The body 
wall is composed of three layers, (1) an outer cellular layer, the ectoderm 
(Fig. 131), (2) an inner cellular layer, the entoderm, end (3) a tissue 
between them called the middle or supporting layer which is skeletal in 

This middle tissue in all cmlenterates but the Ctenophora is pri- 
marily non-cellular, being a secretion of the cellular layers, and is called 
the mesoglea; in the simplest 
cases {Ilydrozoa) (Fig. 131, A) 
it remains non-cellular, but in the 
larger and more complex forms 
(Fig. 131, B) it becomes cellular 
through the migration of cells 
into it from the ectoderm or 
entoderm. In the Ctenophora the 

Fig. 131 — Diagram 'of a twknterate, middle Invar in nriinnrilv eplliilnr 

with <A) a non-cellular and (B) a cellular nnooie layer is primarily cauuiar, 
™rttn« l»r e e r : . t0derm! S ' « Mo * m! 3> being a development of the em- 
bryonic mesenchyme. 

The ecelenterates are the lowest many-celled animals and ore with- 
out most of the organs and tissues which characterize the highest ani- 
mals. Sexuality is, however, fully developed in alt of them, some being 
hermaphroditic, but the majority being unisexual. Asexual reproduction 
by fission or budding is also very general and leads to the formation of 
extensive colonies. Very many exhibit the phenomenon of alternation 
of generation, in which a sexual, often free-swimming generation alter- 
nates with a sessile, usually colonial and asexual generation. 

History.— This phylum was constituted in 1847 by R. Leuckart, 

who separated the polyps, medusae and Ctenophora (Eschseholtz) from 

the Zoophyta-Radiata of Cuvier and his contemporaries and called them 

the Cmlenterata. He showed that these animals should be included in 




one and the same phylum inasmuch as they are without a coelom and the 
hydroid and medusa are usually hut stages in the same life history, facts 
the importance of which had only very recently begun to be understood. 
Trembley (1744) introduced the term "polypus" because of the fancied 
resemblance of Hydra to the octopus, the polyp of the ancients. The 
term "medusa" was employed by Linnaeus and the older writers because 
of the resemblance of the tentacles of many jellyfish to the snake-like 
curls of Medusa. 

The phylum is composed of 3 subphyla. 

Key to these subphyla : 

Ox Sponges ; animals sessile, without tentacles 1. Sfongiabxa 

o, Hydroids, jellyfish, corals, etc.; no cilia or outer surface; tentacles usually 

present 2. Cnidabia 

a± Ctenophores ; outer surface with 8 ciliated bands ; 2 tentacles or none. 

3. Ctenophoba 

Subphylum 1. SPONGIARIA. # (Pobifeba.) 

Sessile, aquatic ani- 
mals, with but few spe- 
cialized organs and tis- 
sues, in which skeletal 
fibres or spicules usually 
form an important part 
of the body. The animals 
often live in colonies of 
irregular form in which 
the various individuals 
are indistinguishably fused 
with one another. Numer- 
ous pores in the body wall 
admit water into an in- 
terior chamber called the mg% 182 -i>iagrams of the 3 types of sponges 

cloacal cavity, of which a J 80 ")-., A » ***** type; B, sycon type; C, leucon 
v»Tikj, ui " UIWI » type. 1, osculum; 2. cloaca; 3, pore canals; 4 

large opening called the radial canal ; 5, flagellate chambers. 

osculum furnishes an outlet. Sponges are without tentacles and motile 

appendages of any sort and the adult forms have no locomotory 


• See "Rep. of Invertebrate Animals of Vineyard Sound and Adjacent Waters/' by 
A. B. Verrill, Rep. of U. S. Fish. Com., 1871. "Poriferata," by A. Hyatt, Stand. 
Nat Hist, Vol. 1, 1888. "Spongiaires," by Delage et Herouard, Trait 6 de Zool. 
concrete, 1899. "Sponges/* by B. A. Minchen, A Treatise on Zoology, 1900. "Sponges 
Collected in Porto Rico," by H. V. Wilson, Bull. Fish. Com., Vol. 20, Pt. 2, p. 875, 
1900. "Catalogue of Recent Marine Sponges of Canada and Alaska," by W. Lambe. 
Ottawa Naturalist, Vol. 14, 1900. "Biological Survey of Woods Hole and Vicinity," by 
F. B. Sumner and others. Bull. Bur. Fish., Vol. 81, 1913. 


The simplest sponges (Fig. 132, A) are usually cylindrical struc- 
tures, either colonial or not, in the walls of which are numerous pores 
through which water streams into the cloacal cavity; the osoulum is at 
the free end of the body. The body wall is composed of three layers, 
the outer ectoderm or dermal epithelium (Fig. 133,1), the middle skeletog- 
enous layer or mesoglea containing the skeletal elements (2), and the 
entoderm (3) consisting of peculiar cells called collar cells or choano- 
cytes which line the interior cavity. Each collar cell is provided with a 
single flagellum, the base of which is surrounded by a high ridge or 

This simple structure is called the ascon type of sponge. Other 
sponges have what is called the sycon type of structure (Fig. 132, B). 
In this the middle layer is much thicker than in the ascon type and from 
the central cavity numerous cylindrical diverticula called the radial 
canals (Fig. 132, B, 4) extend into the walls, and communicate also with the 

outside through pore canals (3). In these sponges the 
collar cells are confined to the radial canals, the central 
cavity being lined with a flattened epithelium. Still an- 
other type of sponge (Fig. 132, C) is called the leucon 
or rhagon type, in which the skeletogenous layer is still 
Fig. 133 thicker than in the sycon type and the collar cells are 

Brora 7£enden- confined to widened portions of the radial canals called 
deVm (wflar " the fla S ellate chambers (5). 

porting lllyer^ ^ e S* 6 ** majority of sponges belong to the leucon 

8, entoderm. type; in these the middle layer constitutes by far the 

greater part of the body of the animals. 
The ectoderm forming the dermal epithelium in all sponges is a 
single layer of flattened cells which in a few cases (Oscarella) is ciliated. 
In many sponges the ectoderm is more or less glandular and in all it is 
contractile, the contractile elements in it being elongated cells called 
myocytes which form sphincters around the pores and oscula and often 
also surround the cloacal and other cavities; the ectoderm is also some- 
times sensitive. 

The mesoglea varies much in thickness in different sponges, being 
generally thin in the smaller and more primitive sponges and thick in 
the higher and larger ones. It arises as a secretion of the ectoderm 
and contains various cellular elements, and usually also calcareous 
or silicious spicules, or horn-like fibres composed of a substance called 

The spicules are of a great variety of forms and fall into two gen- 
eral groups which are called megascleres and microscleres (Fig. 134). 
The former are usually elongate or radiate in form and are often bound 


together by spongin or connective tissue fibres or articulate together to 
form a network, and constitute the supporting framework of the body. 
The latter are minute flesh spicules of a variety of forms which are scat- 
tered throughout the tissues. 

The cellular elements of the mesoglea fall into two distinct groups: 
(1) those which are derived from the ectoderm, and (2) the archeocytes. 
The former migrate into it and are either scleroblasts which secrete the 
spicules, the spongioblasts which secrete the spongin fibres, or the col- 
leneytes or connective-tissue cells which are distinguished by their stel- 
late form and thread-like pseudopodial processes. The archeocytes are 
primitive cells derived from the blastomeres during development, which 
perform a variety of important functions. They are amoeboid cells 
which are nutritive in function, ingesting and digesting food, and also 
supply a circulatory element in that they aid in distributing nutriment. 
They also give rise to the reproductive elements — the spermatozoa, the 
ova, and the gemmules. 
The entoderm con- 
sists uniformly of col- 
lar cells in all sponges. 
The flagella of these 
cells do not act in 
unison, but each for 
itself, and have for 
their main function the 
creation of currents in ° 6 

the water which bring «* ^^^ZSsVSS^SSS^' ** """" 
the animal food and 

oxygen and carry away the wastes. The current thus produced enters 
the pores, traverses the radial canals and flagellate chambers into 
the cloaca! cavity and passes out again through the osculum. The 
food consists of organic particles and minute animals and plants; 
these are ingested and digested by the collar cells in the lower, 
calcareous sponges, but in the greater majority of them principally by 
the amGDboid archeocytes. No special excretory or respiratory organs 
and no muscles, nerves or sense organs are present in sponges, although, 
as we have seen, contractility is present in the ectodermal cells, and sen- 
sitiveness to external stimuli is often noticeable. 

Sponges have three methods of reproduction: (1) by budding, (2) by 
the formation of gemmules, and (3) by sexual methods. Budding is 
simply growth -which results in the formation of new oscula, each oscu- 
lum representing a new individual; it is of very general occurrence. In 
a few sponges the bud becomes separated from the parent sooner or 

c i < 




later and leads an independent life, bat in most of them the bads are 
indistinguishably joined together so that a colony results, the members 
of which form a compact whole. 

Gemmule formation occurs in all fresh-water and some marine 
sponges and is a provision against cold weather in temperate regions 
and in the tropics against desiccation. With the approach of the unfa- 
vorable season, archeocytes migrate to one spot in the middle layer, the 
cells of which secrete a capsule around them. When the sponge dies 
the gemmule falls to the bottom and remains, in the case of the fresh- 
water sponge, until the following spring, when the capsule bursts and 
the archeocytes within move out and develop into a sponge. Many 
fresh-water sponges live through the winter, however, notwithstanding 
the formation of gemmules. 

Some sponges are hermaphroditic, others are unisexual. No special- 
ized sexual organs are present, the ova and spermatozoa developing from 
the archeocytes. The ciliated larva swims actively about in the water, 
but finally attaches itself and after a metamorphosis develops into the 
adult animal. 

Sponges are world-wide in their distribution and, with the exception 
of the Spongillidae, are all found in the sea, where they range from 
tide lines to very great depths. The fresh-water sponges occur in lakes 
and streams in all countries. 

History.— Aristotle was acquainted with sponges and knew that 
they were animals, although he notes their likeness to plants. Through 
the ages following his times, opinions differed concerning them, some 
people believing them to be plants, others animals, while many ascribed 
both an animal and a plant nature to them. Ellis (1765) first described 
the currents of water which stream into and out of sponges. Lamarck 
classified them with polyps. Robert Grant (1825) definitely proved 
their animal nature, showing that water flowed into the sponge through 
numerous minute pores and out through the oscula, and he correctly 
inferred that ciliary action caused the flow. Many competent natural- 
ists, however, still believed them to be plants, and the question was not 
finally settled until about 1870 or later. H. J. Clark (1866) first demon- 
strated the collar cells and laid the foundation for the belief which pre- 
vailed for some time that sponges are colonial flagellate Protozoa. The 
embryological investigations of F. E. Schulze and others, however, have 
tended to overthrow this belief, and sponges are at present usually 
classified under the Metazoa either as a separate phylum or under the 

The Spongiaria include about 2,500 living and a large number of 
fossil species, and are grouped in 3 classes. 


Key to the classes of Spongiaria: 
o. Small marine sponges with calcareous spicules and large collar cells and 

mostly under 2 cm. in length 1. CiiCUu 

a, Usually larger sponges with ailicioUB spicules or spongin fibres, or both, or 
without either. 

b. Glass sponge*; spicules usually six-rayed 2, HtXACTrnxLUnA 

b, Massive sponges without six-rayed spicules; skeleton of silicious spicules, 
spongin or both, or wanting 3. Dekobfonoue 

Class 1. CALCABEA.' 

Marino sponges of small Bine with 1-rayed, 3-rayed or 4-rayed cal- 
eareoas spicules; most of them are cylindrical in shape, colorless, either 
solitary or colonial, and live in shallow water; 2 orders with about 150 

Key to the orders of Calcarea: 
•t Body wall thin and porous ; central cavity lined with collar cells. 

1. ~~ 
a, Body wall not thin ; central cavity without collar cells 2. Hbtxbocceu 

Obdeb 1. HOMOOtELA. 

Very simple, thin-walled sponges in which the central cavity eon* 
tains the collar cells; each pore in the body wall is a perforation of a 
single thickened dermal cell leading into the cavity: 2 families and over 
50 species. 


With the characters given above; no radial canals or flagellate 
chambers; with straight, triradiate, or qnadri radiate spicules: 4 genera. 

1. LstroosOLMiA Bowerbank. Usually 
colonial, although sometimes simple 
sponges, consisting of a mass of narrow 
anastomosing tubes: numerous species. 

L. botryoides Bow. (Fig. 135). Sponge 
up to 35 mm. long, ivory white in color, and 
consisting of a mass of slender tubes; 
spicules 1 and 3-rayed and faint yellow in 
color: in shallow water; Martha's Vine- 
yard to Gulf of St. Lawrence; Europe. *-*- 1 ^ e J% ^^ N " nh 

L. cancellata Verrill. Sponge massive, 
consisting of small anastomosing tubes, up to 3 em. in length and yel- 
lowish in color: walls thin, with triradiate and qnadriradiate spicules: 
Caseo Bay to Arctic Ocean. 

* See "Die Kalks-fawlmme," b- EL Haeekel, 1873. 


L. fragilia* Haeckel (Ascortis fragiUs Haeek.). Color white or yel- 
lowish; spicules both straight or somewhat arched and triradiate; sep- 
arate individuals 1 to 1.5 mm. long; colony 5 to 10 mm. in diameter: in 
shallow water from Long Island Sound to Gulf of St. Lawrence; 
common; Europe. 

Order 2. HETEROCtELA. 

Small sponges usually more or less cylindrical in form with thick 
walls and a cluneal cavity lined with a flat epithelium and not with col- 
lar cells, the latter being confined to more or less well-defined chambers 
or in radial tubes which are joined by means of small inhalant dermal 
canals with the outside; either solitary or colonial: 6 families and about 
90 species. 

Family 1. GBANTIIDAE. 

Radial tubes extending outwards from the cloacal chamber; distinct 
and continuous layer (dermal cortex) peripheral to the radial canals; no 
conspicuous quadriradial spicules lin- 
ing cloacal cavity: about 13 genera and 
40 species. 

1. Gbahtia Fleming. Triradial 
spicules filling mesoglea and projecting 
into cloacal cavity; cortex thin: 20 

0. dliata (Fabricius) (Fig. 136). 

Solitary sponges, 12 mm. high and 3 

mm. thick; 2 kinds of mouaxial spic- 

P!g.l88-Or a »H-rti«.( (KelioK). uleB > * lon & r kind protecting the 

K 'E&£l&t l £t3£ tB - ° flcnlnm ftnd » 8horter in the eortM 

protecting the inhalant canals: Rhode 
Island to Greenland, from low water line to 60 fathoms; Europe; often 

G. canadensis Lambe. Body 3 mm. high and 1 mm. thick: Gulf of 
St. Lawrence and northerly. 


Collar cells in spherical flagellate chambers from which branched, 
exhale nt canals extend to the cloacal cavity : 5 genera. 

Leucamdra Haeckel. Spicules without regular arrangement; many 

Bpongiarul 77 

lb taylori Lambe. Sponge small, solitary, globose, 6 mm. high and 
45 mm. thick, with thick walla and a narrow cloaca! cavity; spicules 
triradiate, with long monazialfl protecting the osculant: Vancouver 

Family 3. AMPI10BI8CIDAE. 

Conspicuous subdermal quadriradiate spicules with elongated in- 
wardly directed rays: 5 genera. 

AxFHOUSOun Hacckel. Cortex thin; spicules triradial and quadri.- 
radial: several species. 

A. thompaoni Lambe. Golf of St. Lawrence. . 

Cubs 2. HZXAGTINELLIDA.* (Tkiaxonia.) 
Glass sponges. Sponges with usually rather thin walls and a large 
cluacal cavity giving them a more or less tubular or basket-like shape; 
spicules Bilicious, consisting of 3 crossed axes making them either 6-rayed 
or belonging to the 6-rayed type, and either soli- 
tary or joined to form a continuous skeleton 
which often has the appearance of spun glass; 
cloaca! cavity large and unusually more or lees 
cylindrical, usually with simple radial flagellate 
chambers opening out from it, the wall of the 
cloaeal cavity, however, often folded and the 
chambers branched: about 12 families. 


Body elongate, usually curved or twisted; 
spicules joined together forming a network; 
upper end the larger with a terminal sieve-like 
plate; lower end with usually a mass of long 
silieious threads which fastens the animals in 
the mud: several genera. 

EirFUomu Owen (Fig. 137). With the characters of the family:' 
several species. 

E. inheres Wyville Thomson. Body a straight, cylindrical, slightly 
swollen tube, 25 cm. long and 5 cm. in diameter : West Indies, in deep 

Family 2. HT ALONEMATtD AE. 

Body globose, elongate or cup-shaped with a long stalk composed of 
long twisted silieious strands; several genera. 

Htaxostkha Gray. Body funnel or cup-shaped: several species. 

• See "Report on the HeuctlnelUda," by ¥. B. Bcfaoln, Ctall. Rep., VoL 31. 188T. 


H. longiiwimnm Verrill. Length 40 em. : in 60 to 95 fathoms off the 
New England coast. 


Usually massive and often brightly colored sponges with thick walls 
and small round flagellate chambers connected by branched exhalent 
canals with the cloacal cavity; spicules very varied in form, being often 
monaxonic and straight and needle-like, or tetraxonic with 4 crossed axes, 
giving them 8 rays; spongin either present with the spicules or not, or 
the fibres alone may be present or both be wanting: 4 orders. 

Key to the orders of Demospongiae : 

Ox Skeleton formed of tetraxonic silicious spicules of a variety of forms without 
needle-like spicules and without spongin ; in rare cases no skeleton. 


Oa Skeleton of needle-like spicules with often others and with or without spongin 

fibres 2. Monactinellida 

a, Skeleton of spongin fibres alone 3. Cebaospongiae 

a« Skeleton entirely wanting 4. Myxospongiae 


Sponges with usually a hard outside crust or cortex containing 
megascleres which form the principal framework of the body, micro- 
scleres occurring throughout the mesoglea and being of a variety of 
forms, but usually reducible to the tetraxonic type : 8 families and over 
325 species. 

Family 1. THENEIDAE. 

Body usually more or less mushroom-shaped with the osculum in the 
center: 1 genus. 

Thxnsa Gray. With the characters of the family: several species. 

T. echinata Verrill. Body 5 to 10 cm. broad and not quite so high, 
with a short, thick stalk ; upper portion with radiating bundles of spicules 
which project beyond the surface : New England coast north of Cape Cod. 

Family 2. GEODHDAE. 

Body globose with a thick crust, provided with masses of spherical 
spicules: about 8 genera and 180 species. 

Gsodia Lamarck. Tetraxonic needles radially arranged and con- 
fined to the periphery; oscula sieve-like, in groups; incurrent openings 
also sieve-like and scattered : 70 species. 

G. mulleri (Fleming). Spherical or flattened in youth, later irregu- 
larly lobed; diameter and thickness sometimes 30 cm.: cosmopolitan; 
Jamaica; West Indies. 

• See "Tetraxonla," by R. von Lendenfeld, Dm Tierreich, 1003. 



Sponges in which the skeleton consists of needle-like (monaxonic) 
spicules and sometimes other kinds, with or without spongin fibres: 20 
families, grouped in 2 suborders, and numerous species, constituting the 
majority of all sponges; mostly in shallow water; 1 family in fresh 

Key to the suborders of MonactinelUda: 

a, Sponge compact, usually massive 1. Hadromerina 

a, Sponge not compact, usually with spongin 2. Halichondrina 

Suborder 1. HADROMERINA. 

Body compact, having a hard outside crust or cortex, and usually 
massive but sometimes cup-shaped or stalked; spongin absent or very 
poorly developed: 8 families. 

Family 1. TETHYIDAE. 

Body spherical, with slight projections on the surface caused by the 
protrusion of the end of bundles of long needles (megascleres) without 
heads which extend radially from the centre of the body; no spongin 
fibres present: 6 genera. 

Tbtkta Lamarck. Body with a thick, leathery rind and the form 
and color of a small orange : several species. 

T. hispida Bowerbank. In 8 to 35 fathoms in Casco Bay, Maine. 


Form massive; substance compact and firm; spicules (megascleres) 
are needles with heads; without microscleres or spongin: 15 genera. 

Btoebxtsb Nardo. Form various, often massive, sometimes pedun- 
culate ; outer surface smooth : 15 species. 

S. compacta Verrill. Body irregular, being an elongated mass 
attached by one edge; length up to 15 cm.; width and height 2 to 8 cm.; 
color bright yellow; surface smooth; oscula inconspicuous: Maine to 
Virginia in shallow water; often on the shells of hermit crabs. 


Form massive, often spherical, with long needles extending radially 
from the centre; with the surface covered with small protuberances, 
some of which have an osculum; no microscleres or spongin: 13 genera. 

Polymastia Bowerbank. Smaller needle and pin-shaped spicules 
in addition to the radial ones present. 

P. robusta Bow. Form irregular; color yellow or gray; diameter 


up to 30 cm.; with finger-like branches 4 to 10 mm. long: North Carolina 
to Maine and northerly in 1 to 8 fathoms; very common in Long Island 
Sound; Europe. 

Family 4. CLIONEDAE. 

Sponges which bore in shells or limestone by some process not 
understood; monaxial spicules of various forms: 4 genera. 

Ozjoka Grant. The sponge begins its existence by boring in the 
dead or living shells of various mollusks; it honeycombs the shell, and 
after having destroyed it, grows over it, forming a mass often 15 or 20 
cm. in diameter, on the surface of which are small elevations. 

0. celata Grant. Sulphur sponge. Color bright yellow: very com- 
mon from South Carolina to Maine in 1 to 12 fathoms; cosmopolitan. 


Body not compact but usually fibrous, without a cortex; spongin 
usually well developed: 13 families. 

Family 1. SPONGILLIDAE. • 

Fresh-water sponges. Body variable in shape and forming an irreg- 
ular mass incrusted on stones, sticks, plants, etc., up to the size of the 
hand, or larger, and yellow or brown in color, or green where exposed to 
the sunlight, as the result of the presence of zoochlorellae ; spicules of 
two principal kinds, (1) the megascleres, slightly curved needles or rods 
occurring in the mass of the sponge and (2) the microscleres, much 
smaller needles, rods or amphidiscs (two star-like plates joined by a rod) 
(Fig. 139, B) which occur in the sponge or form the shell of the gem- 
mules; asexual reproduction by gemmules, these being globose buds 
about .5 mm. in diameter, which may occur throughout the sponge, being 
present mostly in the latter part of the summer and in the fall: about 
10 genera and 50 species, of which 21 occur in this country ; in fresh and 
sometimes brackish water, both in running streams and in ponds and 
lakes, from the surface to a depth of 200 feet; cosmopolitan. 

Key to the American genera of Spongillidae: 

o, Gemmules without tendrils or projections. 

6 t No amphidiscs present 1. Sponqilla 

ft, Amphidiscs present. 
Ox Discs of amphidiscs of same size. 

o\ But one type of amphidiscs 2. Ephydatia 

d, Two types of amphidiscs 3. Heteromeyknia 

Ob Discs of unequal sice 4. Tubklla 

a, Gemmules with tendrils or projections 5. Cabtebtos 

• See "A Monograph of the Fresh Water Sponges," by E. Potts, Proc. Acad. Nat. 
Sci., Phils., for 1887. "Spongillidae," by W. Weltner. Sflssw. F. Dentschl., Heft 
19, 1909. 



<■. Dant). 

i mioroeeleres in body of sponge: in 
oiding the light; next to the above, 

1. Spowaitu Lamarck. Gemmnle without amphidiscs, bat sur- 
rounded by needles or rods alone; large needles usually smooth: 17 
species, fl American. 

S. lacustris (L.) (F%. 138). Sponge branching and usually green, 
with smooth longer (megascleres) and rough shorter (microsclerea) 
needles; gemmnles surrounded by spiny curved rods, but occasionally 
without them, and often scarce until late in the fall: cosmopolitan, pre- 
ferring running water and 
sunlight ; the commonest 
fresh-water sponge. 

S. f ragilis Leidy. Sponge 
not branching, growing in 
flat patches, usually yellow 
or brown but occasionally 
green in color; gemmules 
abundant, in one or more 
layers at the base of the 
sponge; large needles smooth; 
standing and running water and a 
the commonest species. 

2. Ephtdatia Lamouronx (Meyenia Carter). Oemmule with amphi- 
discs all of one type : 17 species, 8 American. 

E. nnviatilis (L.) (Fig. 139). Sponge massive, occasionally lobate; 

color yellow or brown, sometimes green; needles smooth 

or rough with only the tip smooth; no smaller needles 

present: cosmopolitan; in standing and running water, 

preferring the former. 

S. Hxixbomxtxhia Potts. Similar to 
Ephydatia, but the gemmnle has amphidiscs 
of two different types, the less numerous 
being much longer than the other and with 
long hooked rays on the discs : 3 species, all 

ryderi Potts. Sponge massive, 
often hemispherical, lobed, light green in 
color; needles rough, except at the tips; long amphidiscs with spiny 
shaft and discs consisting of 3 to 6 recurved hooks; short amphidiscs 
with usually smooth shaft and large flat discs: eastern and central 
North America, in shallow-flowing water. 

4. Tvbxeu Carter. Discs of amphidise of very unequal size, giv- 
ing it the shape of a collar button; needles rough, sometimes with 
rounded tips; 5 species, 1 American, 


Fig. 139 — Ephydatia 

(Hit. A. entire : 

to a stick: B 

gem ic ale (BQi 

. -itfached 
bldlMs In 
F. Dent). 


T. pennsylvanica Potts. Sponge minute, being 6 mm. in diameter, 
incrusting, gray or green in color; gemmules very numerous: eastern 
North America, in shallow water. 

6. Oabtebxto Potts. Aperture of gemmule with 
a chitinons lining which is prolonged into a tube 
which is expanded at its outer margin and often 
divided into long tendrils: 5 species, 3 American. 

0. tenosperma Potts (Fig.140). Sponge yellowish- 
green; needles rough, both long and short being pree- 
rl *- I40 ent; gemmules with 3 to 5 twisted tendrils which may 

mule at Carfertut be 12 mm. long; ampbidiscs as in Ephydatia: eastern 
(BtiMw^'irrSeut.). United States; on water plants or shells. 

Family 2. CHALINIDAE. 
Form various; usually branched; spongin fibres often well devel- 
oped; spicules needle-shaped; some species form gemmules like fresh- 
water sponges: about 40 genera, all marine. 

Key to the genera of CkaUnidae here described : 

o, Spongin fibres form a regular network 1. Chaliha 

a, Spongin fibres little developed. 

6, Spicules connected at their tips to form a network 2. Renteha 

ft. Spicules confusedly massed together 3. Halicondkia 

1. Okalika Bowerbank. 
Sponges in which the spongin 
forms a regular rectangular 
network in which the spicules 
are imbedded: several species. 

0. ocnlata (Pallas) (Fig. 
141). Finger sponge. Thick, 
more or less Battened, forked or 
digitate stalks with round ori- 
fices 2 itaa. in diameter scat- 
tered over them; color orange 
or red: very common from 
Rhode Island to Labrador, in 
1 to 80 fathoms. 

0. arbnscnla Verrill. Dead 
men's fingers. Body a cluster 
of branches, 10 to 20 cm. long ,«..__* 

, Plf. 141— Vhahna oculata (Shaffer). 

and 5 to 10 mm. in diameter, of 

delicate texture and white or gray in color: North Carolina to Cape Cod 

in 1 to 8 fathoms; very common in Long Island Sound, 


2. Rmxu Schmidt. Form various, very fragile, easily pul- 
verized; Bpongin very little developed; spicules straight needles 
joined at their tips, and arranged to form a network: numerous 

E. mollis Lambe. Body massive, lobate, 9 cm. long, 5 cm. high and 
3 em. thick; oscula large, 5 mm. in diameter; surface roogh; color yel- 
lowish: Labrador; Vancouver. 

3. Haxioohdkia Fleming. Massive sponges of various shapes with 
needle-like spicules confusedly massed together, and with but little 
spongin: numerous species. 

H. panics* (Pallas). Color gray, yellowish or orange: from Rhode 
Island to the Arctic Ocean, in 4 to 8 fathoms; Europe. 


Form various, a distinct network of spongin being present with 
needles of various forms, one of which is C-shaped: numerous genera. 

Fig. 112 Fig. 143 

Fig. 142— Mhmciona prottfera (Wilson), Fig. 143 — StyloteHa heltnphila (Parker). 

1, Ebpbbella* Vosmaer. Amorphous sponges with needle-like spic- 
ules predominating; spongin usually distinct: several species. 

E. flbrexilis H. V. Wilson. Irregular sponges, yellowish-brown in 
color, about 10 cm. in diameter, covered with algae, hydroids, etc., 
with a dermal membrane, beneath which are subdermal cavities; 
spicules few; gemmules formed during the summer: Woods Hole, on 

2. MlOXOOlOMA Bowerbank. Sponge incrusting and irregular in 
form, with straight or bent needle-like spicules and stout spongin fibres: 


M. prolifera (Ellis and So lander) (Fig. 142). Bright-red sponges 
incrusting on stones, shells, etc., when young, rising in digitate masses 
sometimes 15 cm. high: South Carolina to Cape Cod from low water 
mark to 10 fathoms; very common in Long Island Sound. 

3. Stylotella* Lendenfeld. Erect, incrusting sponges with very 
little spongin and with needles in bundles ; no microscleres ; texture soft, 
no hard rind present. 

S. heliophila H. Y. Wilson (Fig. 143). Yellowish sponges, either 
massive or with erect finger-like processes, 5 to 10 cm. long and 5 cm. 
high : common on stones and shells in shallow water, North Carolina. 


Sponges in which the skeleton consists of a close network of spongin 
fibres without proper spicules : 4 families and about 40 genera, which are 
found in tropical and subtropical seas. 

Family 1. SPONGIIDAE. 

Commercial sponges-f Spongin fibres solid, with a slender axial 
core and frequently enclosing foreign bodies, such as sand; flagellate 
chambers small with special openings by canaliculi into exhalent cavities: 
7 genera and about 20 species, the fibrous skeleton of many of which is 
used for commercial purposes. 

1. Ettspokoia Bronn. Body massive with slender spongin fibres 
and very small meshes; simple main fibres usually containing sand, the 
finer connecting fibres without sand: about 12 species; cosmopolitan. 

E, officinalis (L.). Levant sponges. Fibres very elastic; form usu- 
ally more or less globose, often lobed, cup-shaped or lamelliform; color 
in life dark brown, being lighter beneath and on the sides : eastern Medi- 
terranean; Bahamas; West Indies; Australia; in 1 to 100 fathoms; 
several varieties are known, of which the most valuable is the light yel- 
low cup-shaped E. moUissima from Asia Minor. The American variety, 
the so-called glove sponge, is one of the least valuable commercial 

2. Hippospoitgia Schulze. Horse sponges. Body massive and per- 
meated by large, often cavernous canals; fibres delicate and forming 
an irregular network: about 20 species. 

* See "The Reactions of Sponges/ 1 etc., by G. H. Parker, Jour. Bxper. Zool., Vol. 
8, p. 1, 1910. 

t See "Revision of North American Porlferae, Pt I and II," by A. Hyatt, Mem. 
Bost Soc. Nat Hist., Vol. 2, 1875 and 1877. "The Sponge Fishery and Trade," by 
B. Rathbun, U. 8. Com. of Pish., Sect 5, Vol. 2, p. 817, 1887. "The Commercial Sponge* 
of Florida," by H. M. Smith, Bull. U. S. Fish. Com., Vol. 17, p. 225, 1897. "The 
Commercial Sponges and Sponge Fisheries," by H. F. Moore, Bull. Bur. Fish., Vol. 28, 
p. 403, 1910. 


H. gosaypina Hyatt. Sheepswool sponge (Fig. 144). Form vari- 
able; surface with numerous projections, between which are the large 
oseola: Florida and the Bahamas; the most valuable American sponge. 

H. equina Schmidt. Horse sponge; yellow sponge; grass sponge; 
velvet sponge. Body massive, of coarse fibre and with extensive canal 
system: Mediterranean; West Indies; Florida; mnch less valuable than 
the above. 

S. Caoouoxsia Schmidt. Fi- 
bres rather coarse and brittle; main 
fibres distinct from the connecting 
fibres ; meshes large : several species. 

0. spongeliformis H. V. Wil- 
son. Body cylindrical, somewhat 
branching, 25 cm. long, 7 mm. 
thick; texture solid, with stibder- 
mal cavities; surface covered with 
minute conical elevations; dermal 
membrane with numerous shells, 

sand, etc., imbedded in it: West ** "*- "fKJSJ?* ° 0MW,mm 


4. HmcnnA Nardo. Form variable, sometimes very Urge; charac- 
teristic filaments present found in no other sponges, which are 3 or 4 
mm. long, very fine and swollen at the ends: numerous species. 

H. acuta Hyatt. Body 10 cm. high, massive, with several osonla; 
surface with small protuberances; filaments in many places in bundles; 
color gray, in life blackish : West Indies. 


Fibres hollow, without foreign inclusions; flagellate chambers small; 
form various: 4 genera. 

Apltstju Nardo. Form various but usually digitate ; fibres form a 
close network; surface with protuberances: numerous species. 

A. flagelliformifl Carter. Body 10 cm. long, cylindrical, branching, 
7 mm, in diameter, dark red in color : West Indies. 

0sdib4. IfTXOSPOlTOIAE. 

Sponges without skeleton of any kind : 2 families. 


Slime sponges. Body inerusting and soft, with elongate, sac-like 
flagellate chambers: 3 genera. 


HillUHH Dujardin. Body small, soft and irregular, with large 
oscula somewhat elevated: several species, 

H. dnjardinl Johnston. Small, pale-yellow, gelatinous sponges grow- 
ing on red algae: in 5 fathoms, off Rhode Island. 


Jellyfish, hydroids, corals, etc. Aquatic animals, either sessile or 
free-swimming, in which the body possesses a single internal cavity, the 
gaatro vascular space (Fig. 131). This has usually a single opening to 
the outside, which is called the mouth, and is the common digestive and 
circulatory cavity; in the simplest cases it is cylindrical in shape, but in 
the higher and larger forms is much branched, 
forming a system of canals. 

The cnidarians are predacious animals and 
usually possess long vibratile tentacles by means 
of which they take their prey. These tentacles, 
as well as other parts of the body, are provided 
with numerous characteristic organs of peculiar 
structure called the nettle organs or nematocysts 

Fig. 140 Diagram of which render tbem effective instruments in the 

performance of this important function. A nettle 
ua niidocii"" , 3i organ (Pig. 145,3) consists of a spiral, thread-like 
fl!:re; o, T ucuie'ce5? r ™ tube with several barbs at the base which lies 
coiled within a cavity in a specialized cell called 
a cnidoblast (1). The cavity is filled with a poisonous fluid; its walls form 
an ovoid sac, the outer end of which is continuous with the thread-like tube. 
A minute spine, the cnidocil (2), projects from the free surface of the 
cnidoblast into the water and when the surface of the ectoderm is irri- 
tated, either by actual contact or in other ways, the tube is shot out with 

• Bee "Contrlhutious to the Natural History of the V. S.," Vol. 3 and 4, by L. 
Agassi*, 1862. "Invertebrate Animals of Vineyard Sound," by A. E. Verrfll. Hep. U. B. 
Fish. Com., 1871. "Lea Ccelenteres," by Deluge et Htrouard, Trait* de Zoologie 
concrete, Vol. 2, 1901. "Hydrolds of tbe Woods Hole Region." by C. C. Nutfing, 
Bull. U. 8. Fish. Com., Vol. 19. 1899. "Synopsis of North American Invertebrate!, 
Tbe Hydromednsae," by C. W. Hargitt, Fait I, II, III, IV, Am. Nat, VOL 35, pp. 
301, 370 and STB, 1901, and Vol. 3T, p. 331, 1903. "Tbe Hydrolds of tbe Pacific Coast of 
North America," by H. B. Torrey, TTolv. of Cal. Pub., Vol. 1, p. 1, 1903. "Tbe Medusae 
of tbe Woods Hole Region," by C. W. Hargitt, Bull. Bur. Fish., Vol. 24, p. 21, 1904. 
"Notes on Ccelenteratea of Woods Hole," by C. W. Hargitt, Biol. Bull., Vol. 14, p. 99. 
"A Synopsis of the Fixed Hydrolds of New England." by J. B. Kingslpy. Tofts College 
Studies, Vol. 3, p. 13, 1910. "Medusae of tbe World," by A. O. Mayer, 1910. "The 
Hydrolds of tbe West Coast of North America," by C. M. Fraser, Ball, from the Lab. 
Ot Nat Hist, of TJolv. of Iowa, Vol. «, 1911. "Borne Hydrolds of Beaufort, North 
Carolina," by C. M. Fraser, Boll. Bur. Fish., Vol. 30, p. 337, 1912. "A Biological 

(Lendenfeld). 1, cnldo- 



Fig. 146 — The action of nettle 
orgiDB (Toppe). A, a nettle or- 
gan piercing tbe cbltlnona shell 

sufficient force to puncture the skin of email animals (Fig. 146), and the 

poisonous fluid which is thus injected into the wound ma; cause paralysis 

or death. The thread tubes also often 

lasso small animals by winding around 

hairs and other projections of their 

bodies (Fig. 146, B). The nettle organs , 

of the larger jellyfish often inflict a 

painful wound to man. 

The body of the Cnidaria is dis- 
tinctly radiate in structure; in the 
smallest jellyfish and hydroid polyps the 
number of radii is usually four and in 
the larger ones and the Alcyonaria, some 
multiple of four; in the Zoantharia it is 
usually six or a multiple of six. 

Two distinctly different types of 
structures are present among the Cni- 
daria, which are, however, capable of 
being referred to a common fundamental 
form. These are: (1) the hydroid or 

polyp type (Fig. 147, A), and (2) the medusa or jellyfish type (Fig. 147, 
B, or Fig. 154). The first is seen in the simplest form in the fresh-water 
Hydra and the hydropolyps, and in a more complex form in the corals; in 
these animals the body is 
cylindrical in form, one end 
is usually attached to some 
more or less stationary ob- 
ject, while at tbe other end 
is the mouth surrounded by 

Two variations of this 
type are found. In the 
S Scyphozoa and the An- 

* thozoa (Fig. 219) longitu- 

jq dinal mesenterial ridges pro- 

ject prominently into tbe 
gastro vascular space and a 
gullet lined with ectoderm 
imbrella ; ii, maou- is present, while in tbe sim- 
pler Hydrozoa or Hydro- 
medusae these festures are wanting (Fig. 147, A). Cnidarians of the 
hydroid type live in colonies in the majority of cases which often con- 

Fig. 147— The t 

of tbe animal b 

■bow the ii_ 

ard.l 1, month: 2. gastro 
tocle ; 4. exnmbrella ; 5. a 
briam ; 7, velum. 


tain thousands of individuals, and grow from one another by process of 

The medusa type is seen in its simplest form in the usually minute 
hydromedu&ans and in a more complex form in the larger scyphomedu- 
sans. In all these animals the foody is more or less bell or disc-shaped, 
the convex side, which is called the exumbrella, corresponding to the 
attached end of the hydroid polyp, while from the center of the concave 
side, which is called the subumbrella, extends the manubrium, a more or 
less cylindrical but often branched projection, at the end of which is 
the mouth. Tentacles may be present on the manubrium, at the edge 
of the bell, on the subumbrella or the exumbrella, and may be long or 
short and flexible or rigid. 

Two distinct types of medusae are met with. Those of one type are 
called craspedote medusae (Fig. 147, B), because they possess a velum (7). 
This organ is a ridge or membrane containing epithelial muscle fibres, 
which extends inwards toward the manubrium from the entire edge of 
the subumbrella. These medusae are almost all small, being usually less 
than 2 cm. in diameter, although some are larger, JEquorea tenuis attain- 
ing a diameter of 10 cm. and Mquorea forskalea of the Mediterranean 
one of 40 cm. and, excepting the Narcomedusae, have a plain, unscalloped 
edge. Those of the other type are called acraspedote medusae (Fig. 216) ; 
these lack the velum or have it in a rudimentary form and possess a 
scalloped outer edge, as well as other special features; they are also usu- 
ally large, some having a diameter of a meter or more. A certain number, 
however, are small, with a diameter of less than a centimeter. 

In Hydra and the Anthozoa the hydroid or polyp type of structure 
alone prevails, and the animals produce, either by budding or by sexual 
methods, young individuals which develop directly into adults similar to 
the parents. In most Trachomedusae and Narcomedusae, so far as known, 
the medusa type alone prevails, the young developing directly into free- 
swimming medusae. In the Hydromeduaae and Scyphomedusae, on the 
other hand, both types may prevail in the same species, and the phenome- 
non of the alternation of generations is exhibited, an asexual generation, 
which is the hydroid, producing by budding a sexual generation, which 
in these animals is the medusoid generation. The medusoids are either 
male or female and produce embryos called planulae, which after a period 
of free life attach themselves to some fixed object and become hydroid 
polyps, the medusoid buds, in certain cases, remaining attached to the 
parent hydroid, and in others becoming free-swimming jellyfish. 

In all the Cnidaria, the body wall consists of the outer ectoderm, the 
inner entoderm and the middle mesoglea (Fig. 131). The ectoderm consists 
of a single layer of cells, among the inner ends of which are small inter- 


stitial cells and often epithelial muscle fibres and nerve cells. The mes- 
oglea is skeletal in function and a secretion of the two cellular layers; 
in the Hydromeduzae it remains non-cellular and usually thin, but in the 
other Cnidaria, cells migrate into it from the ectoderm and it often be- 
comes very thick, forming the jelly (Fig. 131, 3). The gastrovascular 
space (Fig. 147) is cylindrical in the hydroid; in the medusa it is a 
branched cavity which forms a system of canals. Food is taken into the 
mouth ; in the gastrovascular space it is digested and the products of diges- 
tion are caused to circulate throughout the body of the colony by the action 
of the entodermal flagella or cilia. The sexes are separate in Cnidaria, 
with some exceptions, but usually not dimorphic. The sex cells arise in 
the ectoderm in the lower and in the entoderm in the higher forms. 
Locomotion is accomplished by means of the muscle fibres which are the 
inner projections of ectoderm or entoderm cells. The sessile hydroids 
and Anthozoa move their tentacles about actively and can retract and 
extend the body; the medusae swim slowly through the water by means 
of the muscle fibres in the velum or in the subumbrella. The nervous 
system consists of a plexus of nerve cells and fibres among the muscle 
fibres, some of which, in the medusae, form a double ring in the outer 
rim of the umbrella and in the acraspedote medusae a rudimentary gan- 
glion at the base of each sense organ. The muscles may also be stimu- 
lated directly and without the intermediary of nerve cells or fibres. 
Special sense organs are absent in hydroids and the Anthozoa: in medusae 
they are present in the margin of the umbrella and may be either visual 
(ocellate) in function or equilibria! (vesiculate). 

History.— Aristotle was acquainted with many cnidarians, especially 
with actinians and medusae which he named Acalephae and Cnidae, the 
latter term referring to the stinging power of the animals. During the 
succeeding ages and down to about the middle of the eighteenth century 
the animals were observed and figured by a number of naturalists, but 
little or no exact knowledge of them existed. They were called either 
plants or plant-animals (zoophytes) and were often considered the con- 
necting link between the plant and animal kingdoms, a belief that has 
not entirely disappeared in some localities even down to the present day. 
Polyp stocks and corals were generally held to be plants, the individual 
animals being called the flowers. When, however, Trembley in 1744 
demonstrated the animal nature of Hydra and Peyssonnel in 1753 that of 
corals, a new era began in the study of cnidarians, and in the following 
years a large number of them were accurately figured and described by 
Ellis, Pallas, 0. F. Miiller, and others. The relation of the polyp to 
the medusa was, however, still for a long time to be entirely unknown. 
Cuvier in 1799 was one of the first to study the anatomy of the medusa 


and in 1812 brought polyps and medusae together in the single type- 
group of Animalia-Radiata. 

The next few years saw an immense increase in the knowledge of 
both the anatomy of the medusa and the polyp and in the number of 
the forms known, yet it was not until 1841 that M. Sars, on the basis 
of his studies of Aurelia aurita, and 1842 that Steenstrup, on that of 
his studies of Coryne, could first definitely formulate the principle of 
the alternation of generations in cnidarians and elucidate the relation of 
the polyp to the medusa. Even as late as 1837 Loven held the polyp and 
medusa to be dimorphic sexual forms, the former being the male and 
the latter the female individual. In 1847 Leuckart created the phylum 
Ccelenterata and called attention to the fundamental sack form of the 
body, and in 1849 Huxley showed that the walls of this sack were made 
up of two layers which he named ectoderm and entoderm and homologized 
with the two primitive germ layers of the higher animals. In 1851 Vogt 
introduced the useful term Hydromedusa, Huxley in 1856 that of Hydro- 
zoa, and Clans in 1891 that of Scyphozoa. The latest development of 
the system is due to many authors, of whom perhaps Chun and A. G. 
Mayer are especially to be mentioned. The first important American 
work on cnidarians was J. D. Dana's Report of the Zoophyta of the 
Wilkes Expedition (1846). Louis and Alexander Agassiz and their 
pupils and followers have done the most to extend the knowledge of 
American cnidarians. Mayer's monograph, The Medusae of the World, 
is the most important recent work. The subphylum contains about 4,200 
species, grouped in 3 classes. 

Key to the classes of Cnidaria: 

a, Small bydroid polyps and both small and large medusae. 
b x Hydroids without mesenterial ridges and usually colonial, and craspedote 

medusae 1. Hydbozoa (Hydromedusae) 

6, Minute hydroids with 4 mesenterial ridges, and acraspedote medusae. 

2. Scyphozoa (Scyphomedusae) 
o, Corals, sea-anemones and gorgonians 3. Anthozoa 

Class 1. HYDBOZOA. (Hydromedusae.) 

Hydroid polyps and craspedote medusae, usually with alternation of 
generations. The hydroid stage, which is called the trophosome, is sessile 
and usually colonial and produces by budding the medusoid stage, which 
is called the gonosome. The latter is sexual and either male or female. 
The individual hydroids are small, being usually but a few millimeters 
in length, the solitary tubularians being exceptions, which may be several 
centimeters, and in the case of the deep-sea Branchiocerianthus imperator, 
which is allied to Corymorpha, a meter or more in length. The colonies 
are often plant-like in appearance; the individual polyps are called the 


hydranths (Fig. 152), the stalks on which they grow, the hydrocaulus, 
and the root-like projections by which the stalk is attached to the sub- 
stratum, the hydrorhiza. The gastrovascular space (Fig. 150) extends 
throughout the colony so that all the polyps are in communication with one 
another. A cuticular layer called the perisaxc is secreted by the ectoderm 
of many species which gives rigidity to the whole colony: in the Hydro- 
eoralUnae the perisarc is calcareous and so enormously thickened that the 
colony has the appearance of coral The mouth of the hydroid is ter- 
minal in position and at the summit of an elevation called the hypostome. 

In very many Hydromedusae, the hydroid individuals are polymor- 
phic (Fig. 162), being specialized to perform different functions. 

The medusoid stage or gonosome is either a free-swimming craspedote 
medusa or a sessile medusoid individual or gonophore which remains 
attached to the parent hydroid. In the latter case it may have retained 
the general form of a medusa or it may be reduced to the form of a bud 
(sporosac) and have lost all semblance of the medusoid form. The 
embryo is ciliated and is called the planula: after a period of free life 
it attaches itself and becomes a hydroid polyp. 

Most Hydromedusae live in the sea. Hydra is found in fresh water 
and is cosmopolitan in its distribution. Cordylophora is a brackish water 
form which also occurs in fresh water. A few medusae, Microhydra in 
Pennsylvania and Europe, Craspedacusta (Limnocodium) in America, 
Europe and Brazil, Limnocnida in Lake Tanganyika and Holomisis in 
Trinidad, occur in fresh water. The class contains about 2,000 species, 
grouped in 7 orders. 

Key to the orders of Hydromedusae: 


a, Animals mostly in fresh water 1. Hydbakae 

a, Animals marine (rarely in fresh water). 

6, Colony forms a coral-like stock 2. Hydroooballtnae 

\ Colony not coral-like. 

c, Colony and individual hydroid usually not minnte. 
d\ No protective cup (hydrotheca) on hydranth (Fig. 150) . .3. Tubuiabiae 

d, Hydrotheca present (Fig. 172) 4. Campanulabiae 

<?, Colony and hydroid minute (when present) 5. Tbachomedusae 

c, Colony free swimming 7. Siphonophoba 

(Excluding the HydrocoraUinae and the Siphonophora.) 

Oi Rim of umbrella not scalloped. 

bx Gonads on manubrium 3. Tubulabxak (Anthomedutae) 

b t Gonads on subumbrella (sometimes also on manubrium). 
Ci Medusae often disc-like at maturity. . .4. Campanulabiae (Leptomedusoe) 

c, Medusa usually hemispherical or elongate 5. Tbachomedusae 

Hi Rim of umbrella scalloped 6. Nabcomedubae 



Fig. 148 

Bydra virl&toHma 
(SOmw. F. Dent). 
1, sperm ; 2, ovum. 

Osdeb 1. HYDRARIAE.* (The Hydras.) 

Elongate, cylindrical animals 1 to 3 centimeters in length. The animal 
attaches itself temporarily by means of a sticky secretion at one end 
which may be called the foot, and can move about slowly by gliding on 
the foot and by a looping movement; it cannot swim. At the free end 

is the mouth on the conical hypostome, at the base of 
which is a single row of hollow tentacles. No perisarc 
is present. The food consists of small crustaceans 
and other animals which are caught by means of the 
nematocysts. When the animal is well fed it repro- 
duces principally by budding, the buds often remain- 
ing attached to the parent for a while, but finally 
becoming separated: it also reproduces occasionally 
by transverse or longitudinal fission. At certain times 
the Hydra reproduces sexually and is either monoa- 
cious or unisexual. Spermatozoa are produced from 
specialized interstitial cells usually near the base of the tentacles which 
form rudimentary testes, and a single large ovum may appear in an ovary 
formed of interstitial cells usually near the proximal end of the body. 

The order contains about four genera, of which Hydra 
is the most familiar. The other genera, Protohydra and 
Haleremita, which are marine, and Poly podium, which was 
found on the eggs of the sturgeon in the river Volga, are 
apparently rare and have not been found in this country. 
Hydba L. Tentacles 4 to 12 in number: 3 well 
established species; cosmopolitan; in fresh water. 

H. viridiflsima Pallas (H. viridis L.) (Fig. 148). 
Green hydra. Body grass green, the color being due to the 
presence of zoochlorellae in the entoderm; tentacles short 
and about 6 in number; hermaphroditic: usually on water 

H. oligactis Pallas (H. fusca L.) (Fig. 149). Brown 
hydra. Body brown; tentacles very long and about 8 in 
number; proximal end of body slender and stalk-like; unisexual: on stones, 
sticks, and plants. 

H. vulgaris Pallas (27. grisea L.). Color gray, orange, or brown; 
proximal end of body not stalk-like; average number of tentacles 6: on 
stones, plants, etc. 

Fig. 149 
Bydra oUgac- 



tig (SQbsw. F. 

* Bee "Mem. pour lervir a l'Hlst. d'on genre de Polyps d'ean donee," by A. 
Trembley, 1744. "The Development of Hydra," by G. A. Tannreuther, Biol. Bull., Vol. 
14, p. 261, 1908. "Die Benennung and Unterscheldung der Hydra Arten," by 
A. Braoer, Zool. Ana., Vol. 88, p. 790, 1909. 



Hydromedusans in which the polype ere colonial and have a oaloifled 
perisarc of such thickness that the colonies resemble corals. In fact, 
the animals were classified among the corals until Louis Agassis in 
1859 showed them to be hydromednsans allied to the Tubulariae. The 
colony is inerusted on a rock or some other object and rises erect in the 
form of a more or less arborescent, coral-like body in the water, being 
composed of a network of tubes imbedded in a thick calcareous mass. 
The tubes have the cellular structure characteristic of hydromednsans, 
the calcareous groundwork being secreted by their ectoderm. Numerous 
pores appear in the surface of the colony leading into cylindrical cham- 
bers from the bottom of which two kinds of polyps may project into 
the surrounding water; these are nutritive polyps or gastrozooids, with 
mouth end often provided with tentacles, and the defensive polyps or 
daetylozooids, without mouth and with batteries of nematoeysts. Tho 
gonosomes are usually sporosaes, but in a few forms they are medusae 
and are produced in chambers which open to the outside through special 

The suborder contains 2 families and 15 genera) which are inhab- 
itants of tropical seas. One species occurs on the Florida coast. 


Colony very varied in form, consist- 
ing of a broad basal mass which is in- 
crusted on the rook, and irregular, short 
branches which rise from it into the 
water; the nutritive polyps have each 4 
or 5 short knobbed tentacles ; the defen- 
sive polyps are also provided with ten- 
tacles ; the gonosome is a free medusa with 
4 or 5 rudimentary tentacles: 1 genus. 

Mtllepoea L. Each nutritive polyp 
is surrounded by 5 to 6 long and very 
contractile defensive polype : 1 species on 
the Florida coast and in the West Indies. 

» i-i . w n > « "S- IB*— A tubuHrtan hjrdrold 

M. alclcornu L. Pepper coral. On polyp (Eudendrtum) (Uertwlg). 

.. _ _ .- . , . 1. entoderm ; 2, ectoderm ; 8, perl- 

tne coast of Florida; has unusual sting- _ ~"~" ' 

ing powers. 

Ohdee 3. TUBULARIAE. (Gyusoblastea ; Anthoubdusae.) 
Mostly eolonial hydromednsans in which the hydranth is without a 
protective cup (hydrotheca) (Fig. 150) and which produce either free 


medusae or sessile medusoid buds. The medusae (Fig. 147, B) are known 
as Anthomedu8ae and are usually more or less bell-shaped and oeellate and 
bear the gonads on the manubrium. Many of them have never been traced 
to the hydroids which produce them : about 15 families. 
Key to the families of Tubulariae here described : 


Ox Hydranth without a basal whorl of tentacles, these being scattered more or 
less irregularly over the hydranth. 

b t Tentacles filiform ; no free medusae 1. Clavidae 

6, Tentacles knobbed 2. Cobynidae 

o a Hydranth with a basal whorl and with or without distal tentacles. 
ft x Hydranth with a basal whorl and no distal tentacles. 
Cx Colony arborescent. 

dx Hypostome conical ; free medusae present 3. Bougainvilliidae 

d % Hypostome trumpet-shaped; sporosacs present 4. Eudendbiidae 

c f Colony not arborescent, but incrusting. 

dx Sporosacs present and no free medusae 5. Hydbactintidae 

d, Medusae present. 6. Podooobtnidae 

b t Hydranth with both basal and distal tentacles. 

Cx Distal tentacles knobbed 7. Pennabudae 

c t Distal tentacles filiform ; hydranths of large size. 
dx Free medusae present. 

€x Hydranths solitary 8. Cobyicobphidae 

Cj Hydranths colonial 9. Dendboclavidae 

dt Sporosacs in pendant clusters present 10. Tubulabudae 


(The 1st, 4th, 5th and 10th families produce no free medusae.) 

Ox No oral tentacles or lobes present. 

h x Two or 4 marginal tentacles. 

c x Tentacles well developed 2. Cobtnidae 

Cx Tentacles rudimentary 7. Pennabudae 

6, One long marginal tentacle, the others short (except Ectopleura) . 


a. Oral tentacles or lobes present. 
bx Marginal tentacles in 4 or 8 clusters (except Perigonimus) . 

3. BouoAiNvnxnDAE 
bx Tentacles not in clusters. 

Cx Marginal tentacles 2 or 4 i Perigonimus 

Ct Marginal tentacles 4 or 8 6. Podooobynidae 

Ct Marginal tentacles numerous 0. Dendboclavidae 

Family 1. CLAVIDAE. 

Trophosome : colony either branching or consisting of an extensive, 
filiform hydrorhiza from which rise the polyps; hydranths elongate and 
bearing numerous filiform tentacles irregularly placed. Gonosome : gono- 
phores in clusters either just below the tentacles or on special branches 
or even rising independently from the hydrorhiza, forming sporosacs and 
never medusae: about 5 genera. 


Key to the genera of Clavidae here described : 

Ox Colony not branching*; polyps rising from a filiform hydrorhiza. 

&! Sporoeacs borne on hydranths 1. Glava 

b, Sporosacs spring from hydrorhiza 2. Rhizogeton 

a. Colony branching 3. Cobdtlophora 

L Olava Gmelin. Simple unbranched hydranths rise from a fili- 
form hydrorhiza; this is protected by a perisarc which extends a short 
distance up the hydranth; sporosacs in clusters at 
the base of the tentacles : 5 species. 

0. leptostyla Agassiz (Fig. 151). Hydranths 
reddish in color, about 2 cm. long, with about 20 
tentacles; male sporosacs pink, female purple: 
common in shallow water on f ucus, piles, etc., from 
Long Island Sound to Labrador; California. 

2. Bhxzogetov Agassiz. Similar to Clava, 
except that the sporosacs arise from the hydro- 
rhiza on short stalks: 1 species. 

B. fusiformis Ag. Hydranth about 8 mm. m fi st lto^%mng)T 
high, with 12 tentacles; sporosacs shorter and 
invested with the perisarc: in rock pools in Massachusetts Bay. 

3. Coedtlophoka* Allman. Colony profusely branching, the hy- 
dranths with scattered filiform tentacles being at the ends of the 

branches; sporosacs ovate, 
.-/ *k> springing from the 

branches; with a definite 
^^ perisarc: 2 species. 

152). Colony about 20 to 
WtF 11 li^l\ ♦ 30 mm. high; hydranth with 

10 to 20 tentacles : on rocks, 

eel grass, etc., in brackish 

and fresh water, being one 

«£ 'PoS^ JlSJ *s& of the very few fresh-water 

Big. 152 Big. 153 ccelenterates; Rhode Island; 

Fig. is2-coraviopnora lacustris (Sttssw. f. M * 8sachu **te J Illinois; 

Dent), l, hydranth ; 2. hydrocaulus ; 3, sometimes rather common; 

hydrorhiza. Fig. 153 — Syncoryne f 
mirabiUa (Agassis). Europe. 

Family 2. COBYNIDAE. 

Trophosome: colony branched or not, with long, slender hydro- 
caulus and cylindrical hydranths bearing numerous knobbed tentacles 

* See "Hydroids In the Illinois River," >y F. 8mlth, Biol. Bull., Vol. 18, p. 67, 1910. 


irregularly placed. Gonosome: gonophores usually among the nasal 
tentacles and producing either free-swimming or attached medusae with 
4 radial canals and 4 tentacles: numerous genera. 
Key to the genera of Corynidae here described: 
a, Hydroid branched; medusa with 4 long, marginal tentacles. . . .1. STNOoim 
a, Hydroid branched ; medusa with 4 short knobbed marginal tentacles. 


a, Hydroid not branched : medusa with 2 long and 2 rudimentary marginal 

tentacles 3. Gmiuxu 

1. Stmcortke Ehrenberg. Hydroid colony 15 mm. high and branched 
and with definite perisarc and an elongate, cylindrical hydranth; medusa 
with an ocellus at the base of each tentacle: 16 species. 

8. mirabilie Agassiz (Fig. 153). Hydroid col- 
ony attached to seaweed, shells, etc., in shallow 
water, from Martha's Vineyard to Greenland, also 
in California; medusoid in 2 varieties, one, which 
was first described as Sarsia mirabilis, free-swim- 
ming, developing in early spring, 7 mm. high and 
4 mm. in diameter, with 4 long, marginal tentacles 
and a long manubrium extending beyond the velum 
(Fig. 154) ; the other, a sporosac, with rudimentary 
tentacles, and without ocelli or mouth. 

2. Dipttbiha MeCrady. Hydroid like Syn- 
coryne; medusae with 4 stout marginal tentacles 
the ends of which are knobbed, and a long 
F |»JraMU(/'mednw" manubrium with constrictions, often extending 
(Harjltt). beyond the velum: 6 species. 

D. Btrangulata McCr. (Fig. 155). Medusa very transparent, 3 mm. 
wide, 4 mm. high, ovoid in shape: common at Woods 
Hole; South Carolina. 

3. OmnmiA HcCrady. Hydroid like Syncoryne 
but unbrancbed, the hydranth rising from a creeping 
hydrorhiza ; medusa with 2 marginal tentacles, each of 
which bears long-stalked nematocysts, and with mouth 
without marginal lobes: several species. 

G. gemmoxa McCr. Hydroid on Mytilus sheila, 
etc.; adult medusa 6 mm. in diameter, almost spherical 
and with 2 tentacles; no ocelli: Vineyard Sound and 

Trophosome: colony branching with distinct, often annnlated peri- 
sarc; hydranth with a single whorl of filiform tentacles. Gonosome: a 

Dipurma j<ra»- 


free-swimming medusa which is usually borne on the hydrocsulus and 
has 4 radial canals; marginal tentacles either single or in clusters, and 
4 or 8 manubrial gonads : about 19 genera. 

Key to the genera of Bougainvilliidae here described : 

a, Hydroid 0010117 arborescent; medusa with tentacles in dusters, 
b, Medusa with tentacles in 4 clusters. 
c, Medusa without short knobbed tentacles ; hydroid arborescent. 

1. Boooainttixi* 

c. Medusa with a pair of short knobbed tentacles at each cluster. .G. Nbuophih 

6, Medusa with tentacles in 8 clusters ; hydroid like Bougalnvlllia. .4. Rathkea 

a, Hydroid colony with creeping hydrorhiss ; medusa with only 2 long tentacles. 

6, Four short oral lobes 2. Febioonihus 

i. Four long orsl lobes 8. Stokotoca 

1. Boo-QAurviLLiA Lesson. Trophosome : col- 
ony arborescent with a dense pcrisare, hydranth 
with conical bypostome. Gonosome: medusa 
globular, with branching oral tentacles and 4 
pairs at first and later 4 groups of marginal 
tentacles : 20 species. 

B. carolinensis (McCrady) (Fig. 156). Col- 
ony may be 25 em. high, usually 7 to 12 em.; 
bypostome conspicuous; tentacles about 12; 
medusa with brick-red manu- 
brium and black ocelli, 4 mm. 

in diameter: Cape Cod and m ise-Bow***!*, 
southward; co mmo n on fueus, pammmli (Bargitt). 
piles, etc. 

B. snperdliaris Agassiz (Fig. 157). Colony 5 cm. 
high or less; bypostome inconspicuous; tentacles 15 to 
20 ; medusa with yellowish manubrium and black ocelli, 
10 mm. in diameter: Newport to Greenland; on fucus 
and shells; Europe. 

2. FzBiooamnra Sars. Trophosome : colony branch- 
ing a little and rising from a retieulated hydrorhiza 
with a gelatinous perisaro and conical bypostome. 
Fig. 1ST Gonosome: medusa with 2 or 4 marginal tentacles; no 

Boatfoinviata ocelli : 10 species. 

"ISESi)? p - J ""! Osbom and Hargitt. Hydroid colony, 10 

mm. high or less; hydranth with 10 tentacles; medusa 
hemispherical with an apical projection, 2 mm. high and broad, with 2 
long tentacles and 2 additional tentacular bulbs; manubrium short, 
squarish, with 4 oral lobes: on spider crabs (Libinia) at Cold Spring 
Harbor, L.L 


3. Stomotooa Agassiz. Trophosome like Perigonimus. Gonosome: 
medusa more or less conical with an apical projection; with 2 long mar- 
ginal tentacles and & squarish manubrium and 4 oral lobes 
and the often very large gonads on the side: 6 species. 
S. apic&ta (McCrady) (Fig. 158). Hydroid form 
unknown; entoderm of manubrium greenish in color in the 
male and brownish in the female; base of the tentacles 
purplish or yellowish; size 4 mm. by 3 mm.: Florida to 
Vineyard Sound; Europe. 

8. rugosa Mayer. Similar to preceding, but with 14 
rudimentary marginal tentacles together with the 2 long 
ones; base of the tentacles and manubrium brick red; 
5 mm. high: common at Newport, R. I., and southwards. 
Brandt (Liaaia 
Trophosome unknown. 
Gonosome : medusa subcorneal with 
margin si tentacles in 8 clusters of 3 
to 5 each; young with only 4 ten- 
tacles ; manubrium buds off young 
medusae; 4 branching oral tentacles; 
no ocelli: S species, 

B. grata A. Agassiz (Fig. 169). 

Medusa 3 to mm. high, transparent: Massachusetts 
Bay to Newport, R. I.; often common. 

5. Nemo ps is Agassiz. Trophosome like Bou- 
gainvillia except that the medusae arise from the 
hydranths. Gonosome: medusa like Bougainvillia 
but with a pair of short-knobbed tentacles directed 
upwards from each group of long tentacles and with 
gonads extending on to the subnmbrella: 2 species. 
N. bachei Ag. (Fig. 160). Medusa 6 to 10 mm. 
high: Florida to Vineyard Sound; common. 

Family 4. EUDENBUDAE. 

Trophosome: colony branching, rising from a reticulated hydro- 
rhiza; perisarc distinct and variously annulated; hydranth with trumpet- 
shaped hypostome (Fig. ISO) and a single whorl of filiform tentacles. 
Gonosome: no free medusae; male sporosacs in a wborl just beneath, 
and the female sporosacs usually just above the tentacles and occasion- 
ally on the hydrocanlns : 1 genus. 

BirsnDUUM Ehrenberg. With the characters of the family : about 
8 American species. 

Fig. J59-~Sathkea grata (Hargitt). 


Key to the species of Ewknriidae here described : 

a, Colony large (8 to IS cm. high). 

b, Branches annulated at their base only B. rubMHH 

ft, Branches completely annulated E. imspam 

a. Colony email (ten than 3 cm. long) B- TE5UE 

E. ramosnm (L.) (Figs. 150 and 161). Colony profusely branched, 
10 to 15 cm. high, with symmetrical branches; tentacles about 20; male 
sporosacs reddish and in moniliform clusters; female sporosaca orange 
and pyriform: abundant on piles, rocks, etc., in shallow water from 
North Carolina to Labrador; Pacific Coast; Europe. 

E. diapar Agassis. Colony less profusely branched than above, 

Fig, lol Fig. 163 

Fig. 101 — Ewlmdrlum ramotum {from Hargitt). Fig. 102— Hvdractinia rchinata 
(McMarrtch). 1, feeding hjHraDtb; 2, defeaatve 

hydrenth ; 3, reproductive bjdranth. 

6 to 10 em. high; tentacles about 28; sezee distinct: in deeper water 
from Vineyard Sound to Bay of Fundy. 

E. ten no A. Agassi z. Colony irregularly branched, 25 mm. in height ; 
male sporosacs moniliform and pink; female sporosacs orange and scat- 
tered over the hydrocaulus : on seaweed, etc., in shallow water from 
Buzzard's Bay to Bay of Fundy; not abundant. 


Trophosome : colony intrusting, the polyps rising separately from 
an intrusted, spiny hydrorhiza to which the periaarc is confined, and 
polymorphic, consisting of 3 types of individuals: (1) feeding hydranths, 
which have a single whorl of tentacles; (2) reproductive individuals, 
bearing* clusters of sporosacs; and (3) defensive individuals usually 
without tentacles but with numerous nematocysts at the apex. Gono- 
some: sporosacs and no free medusae present: 1 genus. 


Hydractihia Van Beneden. With the characters of the family: 
2 American species. 

H. echisftta Fleming (Fig. 102). Colony 10 mm. high; reproductive 
individuals without tentacles: usually on the shells of hermit crabs but 
also on stones, fucus, piles, etc.; very common on Atlantic coast; Europe. 

H. milleri Torrey. Colony 5 mm. high; reproductive individuals 
with tentacles: California, 


Trophosome: like that of Jlydradiniidae. Gonosome: free medusae 
present, each with 4 radial canals and 4 or 8 or more marginal tentacles: 
several genera. 

Key to the genera of Podocorynidae here described: 
a. Medusa with long tentacles, hydroid on LimvXat, shells of hermit crabs, 

etc 1. Podocobtbb 

a, Marginal tentacles of medusa rudimentary ; hydroid on Nairn. . .2. Stylactib 

1. Podocobyne Sftrs. Trophosome: like Hydr actinia. Gonosome: 
medusa globular with 8 or more rather thick tentacles: 11 species. 

P. caraea Bars (Fig. 103). Medusa very transparent, 3 mm. high, 
with 4 marginal tentacles in the young and 24 to 32 in the adult; 
manubrium reddish with 4 oral tentacles : 
hydroid on Linmlus, crabs, rocks, etc. 

P. fnlgarane (A. Agaasiz). Medusa 1 
ram. high, hemispherical, with 8 marginal and 
4 oral tentacles; manubrium buds off young 
medusae: North Carolina to Massachusetts 
Bay ; common ; often brightly phosphorescent. 
2. Styxaotib Allman. Trophosome: col- 
ony consisting of very long, slender hydranths 
rising from a reticular base. Gonosome: a 
sporosac in the European species, but in the 
American a medusa with rudimentary ten- 
tacles: several species, 2 American. 
8. hoopori Sigerfoos. Hydranths 20 mm. long with 18 to 25 ten- 
tacles; medusa globular, 1 nun. in height with 8 rudimentary, marginal 
and no oral tentacles and borne on specialized hydranths, just below the 
tentacles; no ocelli: Long Island and Vineyard Sounds, on Naasa 


Trophosome: colony regularly branching; hydranth with a basal 
whorl of 10 to 12 filiform tentacles and also a number of short knobbed 



tentacles on the hypostome. Gonosome: either a free or a sessile 
medusa with 4 radiating canals and 4 rudimentary tentacles: about 7 

PiKVAXia Oken. With the characters of the family: about 6 

P. ttarelU (Ayres) (Tig. 164). The bright pink hydroid colony 
may be 15 cm. in height, and is attached to piles, rocks, or seaweed in 
shallow water; medosoid buds on the side of the hydranth; medusa 

Pig. 166— 

(Fig. 165) an elongated bell about 2 mm. long with 4 rudimentary ten- 
tacles; the medusa is free-swimming chiefly during midsummer, the 
greater part of the year it is more or less sessile : common from Maine 
to Florida. 


Trophoeome: hydranths solitary and 
of large size with a basal and several 
distal whorls of filiform tentacles; me- 
dusae produced just within the basal 
tentacles. Gonosome: free medusae with 
4 radial canals and 1 to 4 marginal ten- 
tacles, one of which is longer than the 
rest: several genera. 

1. CoBTitoapKA Sars. Large soli- 
tary polyps with a soft striated outer 
surface and no well-defined perisare, 
rooted by filamentous processes : 5 species. 

0. pendula Agassiz (Fig. 166). 
Polyp pendant, 3 to 10 cm. high and 
bright pink; medusa bell-shaped with a 
1 large and 1 to 3 rudimentary marginal tentacles; manubrium extends 

projection at the apes, with 


to the velum; length 6 mm: common from Vineyard Sound to Gulf of 
St. Lawrence in 8 to 30 fathoms. 

2. Htbooodov Agassis. Trophosome: polyp large, solitary, with a 
well-defined perisare and hydrorhiza; hydranth with a basal and 2 distal 
whorls of filiform tentacles; just within the base of the former medusae 
are budded off: 2 species. 

H. prolifer Agassis (Fig. 167). Orange-colored bydroids 4 cm. high, 
with longitudinally striated perisare which is annulated just below the 
hydranth; medusa hemispherical and asymmetrical, with 5 medidional 
orange-colored bands at maturity and with 1 to 3 long marginal ten- 
tacles, from the thick base of which secondary medusae bud: on rocks in 
clear water from Vineyard Sound to Massachusetts Bay; not common. 

3. EoTOFUtUBA Agassiz. Trophosome : hydroid like Tubularia, being 
indistinguishable when without gonophores. Gonosome: free medusae, 

FIB. 167 Fig. 168 Fig. 169 

Flf. 167- EyOncoion preUfer (Mayer). Ft*. 168 — Bcfoplearo oohracca (Hargltt). 
Fig. leo—Turrituptlt nuMcula (Mayer). 

rather elongate, with 2 or 4 tentacles from the base of which lines of 
nematocysts extend on the surface of the bell to its apex : 3 species. 

E. ochracea A. Agassiz (Fig. 168). Medusa about 3 mm. in height 
with a large manubrium and 8 longitudinal bands of nematocysts on 
exumbrella: Cape Cod to South Carolina; common. 


Trophosome: colony branching, with an elongate hydranth at the 
end of each branch bearing IS to 20 short Aliform tentacles scat- 
tered over it. Gonosome: a free-swimming medusa produced below 
the hydranth: 2 genera. 

1. TmuuTonn McCrady. Hydroid form as above; medusa hemi- 
spherical, with 8 to 70 equidistant tentacles; 4 reddish gonads: 1 species. 

T. nntricula McCrady (Fig. 169). Medusa 4 to 5 mm. in diameter: 
Cape Cod to Florida ; often e 



Trophosoine: polyps solitary or colonial, of large size and bright 
pink in color; hydrant ha with a basal and a distal whorl of filiform ten- 
tacles. Gonosome: medusoids remain attached to the polyp, being sus- 
pended from long-branched stalks above the basal tentacles and varying 
in form from sporosac b to perfect medusae; no free medusae; the female 
medusoids produce peculiar free-swimming hyd mid like bodies called 
actinules : 1 genus. 

Tvbvxakia L. With the characters of the family : about 20 species. 

Key to the species of Tubularia here described : 

a, Polyps onbrancbed, Id troops of 4 to 8; medusoids with distinct radial 

canals T. couthouyi 

a, Polyps branched; often no distinct radial canals in meduHoids. 

6, Hydranth with collar T. larynx 

b. No collar present. 
c, Hydranth large; often In muddy water. 

d, Sporosac with conical apical process T. spkctabiws 

d, Female sporosac with flsttened spicsl process T. caocu 

e, Hydranth small ; often in elear water T. tinelu 

T. couthooyi Agassiz (Fig. 170). 
Individuals nnbranched, 7 to 15 cm. 
high; hydranth often expanding 20 
mm. or more, with a basal whorl of 30 
to 40 tentacles ; medusoid with distinct 
radial canals: on sandy bottoms in 
shallow or brackish water, in clusters 
of 5 to 10 individuals; New England 

T. Larynx Ellis and Solander. In- 
dividuals somewhat branched and ex- 
tensively annulated and living in clus- 
ters, 2 to 5 cm. high; a collar-like 

expansion just below hydranth, the "*■ "^~Tj^Sm eo " tho ** t 

Utter with 16 to 20 basal tentacles; 

female medusoid with a conical apical process and no distinct radial 
canals: in shallow water from Cape Cod northwards; California; Europe; 
on rocky and shelly bottoms. 

T. specUbilis (Ag.). Colony irregularly branched, sparsely annu- 
lated, and 8 to 10 em. high, growing in a tangled mass; 20 basal ten- 
tacles: in shallow water from Rhode Island to Bay of Fnndy. 

T. tenella (Ag.). Colony 25 to 40 mm. high and like preceding 
form but more loosely branched: in tide pools and the open ocean; 
Massachusetts Bay to Bay of Fundy. 


Fig. 171 ■••Tvbvlarirt crooea (Aganii*). A, ■ colon; 
B, a single hjunnth. 

T. (Parypka Ag.) 
croce* (Ag.) (Fig. 171). 
Colonies growing in dense 
tufts of long tangled 
sterna of from 8 to 10 cm. 
in height; sparingly 
branched ; basal tentacles 
20 to 24; apical process of 
the female sporosac flat- 
tened: common on piles, 
docks, etc., in shallow 
water from Boston south- 
wards; California. 

Ordeh 4. CAlaTAHDLAEIAE.* (Calyptoblastea; Leptohedusab.) 
Colonial hydromedusana with two kinds of polyps (Fig. 172), the 
bydrantlis or the nutritutive polyps and the blastostyles or the reproduc- 
tive polype. The perisarc does not end at the base of the polyp, as in 
the tnbnlarians, but continues over it, forming, in the case of the 
I hydranth a protective cup called the hydro- 

tfaeea and in the case of the blastostyle a 
cylindrical capsule called a gonangium or a 
gonotheca. In some species the open end of 
the hydrotheca may be closed by projections 
or valves which form an operculum (Fig. 
173) ; in some species also the blastostyle 
projects out of the mouth of the gonangium 
and forms a large cap- 
sule or brood chamber 
in which the eggs de- 
velop, called the acro- 
cyst (Fig. 178). The 
hydranth has never 
more than a single * 

whorl of tentacles and "*■ 1T3 

CampaDularlan opei> 

Fig. iT2 — a umpunliriu can in most cases be cuia (Nutting), a, 

hydrolS (from Hegner). 1, . .... -two-valied operculum ; 

hvdranth; 2. hydrotbeca ; 3, retracted Within its B, one-valved opercu- 

bustoitfle ; 4, gonanglnm. lum. 

hydrotheca or extended 
beyond it. The blastostyle cannot usually be extended beyond its 
gonangium and produces within it the gonophores; these constitute 

t the San Diego Region," by H. B. Torre;, Dnl. at 



the medusoid generation and may either be liberated as free medusae, 
or, remaining in the gonangium, produce the sexual products there, 
which escape from the gonangium as free larvae. The medusae 
(Fig. 191) are known as Leptomedusae and (except in the Thauman- 
tiidae) have lithocysts and not ocelli as sense organs: they bear the 
gonads beneath the radial canals on the snbumbrella : about 8 families. 
Key to the families of Campanulariae here described : 


Oi Hydrotheca sessile, t. «., not joined to the stem by a stalk ; gonangium contains 
hx Hydrothecae in 2 rows (except Hydrallmania) either opposite to each other 

on the stem or not 1. Sebtularhdae 

6, Hydrothecae in a single row on the stem 2. Plumulariidak 

a, Hydrotheca stalked and bell-shaped. 

b x The gonophores are sporosaes 3. Campanulakiidaje 

6, The gonophores are medusae ; hjdroid forms very little known except in the 
genera Obelia, Clytia, and Laodiceo. 



The 1st, 2nd, and 3d families produce only sporosaes and no free medusae. 

Ox Four simple radial canals; lithocysts and no ocelli present 4. Eucopidae 

a, Radial canals numerous (8-100) 5. 2Bquobeidae 

a, Radial canals 4 or 8; ocelli present and no lithocysts.. 6. Thaumantiidae 

Family 1. 8EETULAEIIDAE.* 

Trophosome: colony usually branching; hydrothecae sessile (not 
stalked), almost all with opercula (Fig. 173) and forming two rows 
along opposite sides of the hydrocaulus (except Hydrallmania). Gono- 
some: gonangia much larger than the hydrothecae, there being only a 
few in the colony, and occurring only at certain times of the year; each 
gonangium contains a blastostyle which produces planulae; no free 
medusae: about 15 genera and 135 American species. 

Key to the genera of Sertulariidae here described : 

a, Hydrothecae in two rows. 
5j Hydrothecae exactly opposite each other. 

Cj Operculum in 2 pieces (Fig. 173, A) 1. Sebtulabia 

c, Operculum in 1 piece (Fig. 173, B) 3. Diphasia 

&) Hydrothecae alternate or subalternate to each other. 
Cx Hydrothecae stand out from the stem. 
d l Hydrotheca with toothed margin ; operculum of 3 or 4 pieces. 

2. Sebtulabella 
d, Hydrotheca with smooth margin ; operculum of one piece. .4. Abietinabia 

c, Hydrothecae closely pressed against the stem 5. Thuiabia 

a, Hydrothecae in one row, the openings turning alternately to the right and 
left 6. Hydrallmania 

* See "American Hydroids, Part II, The Sertularldae," by C. C. Nutting, U. S. 
Nat Ifoa. Spec. Ball., No. 4, 1904. 


1. Ss&ttjlabxa L. Hydrothecae in pairs along the stem, the mem- 
bers of a pair being exactly opposite each other; operculum paired 
(Fig. 173, A) ; gonangia have plain margins and are of simple form : about 
20 American species. 

8. pumila L. (Fig. 174). A simple or more or less branched colony 
1 to 5 cm. high attached by a creeping hydrorhiza, the stem being divided 

into short internodes, each bearing a pair 
of hydrothecae; gonangia oval, sessile and 
often bearing acrocysts, the male gonan- 
* t*V 7 gium being somewhat more slender than the 

female : common on f ucus, etc., between tide 
lines, from New Jersey to the Arctic Ocean ; 
California; Europe. 
As 2 - Sebtulabella Gray. Similar to 

Fig. 174— Sertularta pumila Preceding genus, but differs fTom it in that 
a ( ^loi?1 ) B,t , g P oM tt n glum. the Mrothecae are alternate on the hy- 

drocaulus and not opposite, and possess a 
prominent operculum composed of several pieces; gonangium usually 
deeply annulated: about 50 American species. 
Key to the species of Sertularta here described : 

Ox Margin of hydrotheca with 4 slight teeth. 
bi Hydrotheca annulated. 

c t Annotations only on upper side S. gayi 

c, Annotation complete S. bugosa 

b t Hydrotheca smooth S. polyzonias 

o, Margin of hydrotheca with 3 teeth S. tbicuspidata 

8. rugosa (L.) (Fig. 175). A small colony 2 cm. high, either un- 
branohed or little branched and with annulated stem; hydrothecae 
crowded, annulated and with 4 marginal teeth ; gonangia 
large, annulated and with four-toothed aperture: New 
England coast; Puget Sound; Europe. 

8. gayi (Lamouroux). Colony attaining a height of 
15 cm. and with paired or alternate branches ; hydrothe- 
cae wrinkled or partially annulated and with a four- 
toothed aperture; gonangia elongate, ovate, tapering 
towards both ends, annulated in upper portion : Atlantic 5 

coast; Europe. sertularella 

8. polyzonias (L.). Irregularly branching colony (Kingsley). 
attaining a height of 12 cm.; hydrotheca smooth, with 4 
teeth; gonangium deeply annulated and with 4 teeth: Atlantic and 
Pacific coast; cosmopolitan; common. 

8. tricuspidata (Alder). Colony 12 cm. high or less and slender 
with alternate branches; hydrotheca smooth, with 3 teeth; gonangium 


with deep annuls tions and a bowl-shaped orifice: New England coast; 
common; north Pacific coast; Europe. 

5. Dinum Agassis. Colony mora or less branehing, jointed, the 
hydrothecae in pairs opposite each other and standing out from the 
stem; a single operculum present (Fig. 173, B) ; 

gonangia dimorphic, the female being the larger 
and often annulated, and with a brood poach in 
its distal half, the male with a central tabular 
orifice and 4 spines: 10 American species. 

D. fallax (Johnston) (Fig. 176). Colony 
about 8 cm. high, with simple branching, the 
ends of the branches being often tendril-like; 
gonangia elongate ; female gonangia oval, deeply 
cleft into 4 segments : Massachusetts Bay to 
Bay of Fnndy ; Europe. 

D. rosacea (L.). Colony delicate, about 8 
cm. high, branching alternately ; gonangium with 
longitudinal ridges terminating, in the male, in 
the teeth which surround the orifice: northerly 
New England coast; Europe; common. 

4. Abhtixa&u Kirchenpaoer. Hydrothecae flask- 
shaped and alternate or subalternate with operculum of 
one piece on the aide next to the stem and with smooth 
margin: 16 species. 

A. ahiotina (L.) Sea-fir (Fig. 177). Colony large and 
bushy, being sometimes 30 cm. high or more, with alter- 
nate branching, with very large hydrothecae and relatively 
(Kinesicr) small gonangia; from Vineyard Sound to Labrador; north 
Pacific; Europe. 

6. Thuzabia Fleming. Hydrothecae alternat- ^_ 
ing with each other, more than a pair to an inter- 
node and closely applied to the stem, which is &. 
jointed: 20 species. 

T. thuja (L.). Colony very rigid, sometimes 
25 cm. in height, eigsag in shape and annulated 
near the base; perisarc very dark in color; gonan- 
gia smooth and pyriform: in shallow water on F ^,tM 9 HiainUj^ a ai 
northerly New England coast; Pacific coast; gonsngiuro^ «, aero-' 

T, argentea (L.) (Fig. 178). A large bushy colony, often 20 or 30 
cm. high, branching alternately or dichotomously ; gonangia broad, taper- 
ing towards the base, with a circular aperture and usually 2 spines : very 

Fla. 177 



common ; New Jersey to the Arctic Ocean from low-water mark to 100 
fathoms, usually in rather deep water; Pacific coast; Europe. 

T. cnpressina (L.). A slender, elongated 
colony, often 20 cm. high, branching alter- 
nately and dichotomously; gonangia elongate 
with a prominent spine at each side of the 
aperture: same habitat as the preceding but 
less abundant. 

6, Htsuujuvu Hincks. Hydrotnecae 
in a single row projecting out from the 
hydrocaulus alternately to the right and the 
left; colony pinnately branching: 3 species. 

H. falcate (L.) (Fig. 179). Colony often 
30 cm. high, slender, rather rigid and with 
simple branching; on each branch the second- 
ary branches are very regular and feather-like; 
gonangia ovate and simple : on stones, shells, 
etc., on New England coast and in Long Island 
Sound; Pnget Sound; Europe. 

. branch with hy. 


Trophosome: usually a branched colony with sessile hydranths, 
which are borne in a row on small branches called hydrocladia (Fig. 180) ; 
between the hydranths and on the main stem and branches are nemato- 
phores, small specialized defensive polyps, each of which consists of a 
hydrotheca and an elongated body armed with nematocysts. Gonosome : 
gonangia large, the blastostyles producing planulae and never medusae: 
about 43 genera and over 300 species, being a quarter of all known 
hydroids; about 100 species occur along the Atlantic coast and in the 
West Indies. 

Key to the genera of Plumuiariidae here described: 
a, Gonangia not protected by special branchlets J nematophores trampet-8Qape4 
and movable. 
ft, Hydrocladia do not branch. 
c, Colony not diehotomously branched : the hydrocladia arranged in whorls 

or scattered alone the stem 1. Antennui.abia 

o. Branching dichotomoua ; hydrocladia all arise from the upper side ot 

branches -2. Monobmchas 

b, Hydrocladia forked 3. Schizotbicha 

a, Gonangia protected by special branchlets; nematophores immovable. 

4. Cladocarpus 

• See "American Hydroldx, Part I, The Plnmularidae," by C. C. Nutting, TJ. 8. 
Mat Has. Spec. Ball. No, 4, 1900. 



1. ANTEmrouBiA Lamarck. Main stem of colony simple or 
sparsely branched and attached by a massive hydrorhiza; hydrotheca cap- 
shaped; gonangia borne in the axils of the branches: 6 American 

A. antennina (L.) (Fig. 180). Colony a dense cluster of upright 
stems, often 20 cm. high, obscurely jointed, each internode bearing a 
whorl of fine branches (hy- 
droeladia) on which are the 
hydranths and the nemato- 
phores; gonangia ovate and 
of large size, in the axils of 
the hydrocladia : from Mar- 
tha 's Vineyard to Bay of 
Fundy in 6 to 00 fathoms; 

& Monostjboxab All- 
man. Colony branching 
dichotomously and attaining a height of 15 cm.; hydrocladia spring- 
ing all from the upper side of the main branches: 1 American 

M. Quadridens (McCrady). From Martha's Vineyard southwards. 

3. 8CEXZOTBIOBA Allman. Colony usually a cluster of simple stems; 
hydrocladia arranged pinnately and branched in mature specimens: 
4 American species. 

8. tenella (Verrill). Colony branching dichotomously and attain- 
ing a height of 5 cm.; stem divided alternately into longer and shorter 

Fig. 180 — Antennularia antennina (Nutting). 1» 

hydrants ; 2, nematophore ; 3, gonanglum ; 

4, hydrocladium. 

Pig. 181 

Fig. 182 

Fig. 183 

Fig. 181— SohUotrieha oruoUUma (Nutting). Fig. 182— Cladooarpn* ItoviUt (Nut- 
ting). Fig. 18Z—Holeciwm haleoinnm (Hargitt). 

intemodes, the latter bearing each a hydrocladium; gonangium cornu- 
copia-shaped : Long Island and Vineyard Sounds, in shallow water, often 


8. gradllima (G. O. Sars) (Fig. 181). Colony about 5 em. high; 
branches divided into regular internodes, each bearing a hydrocladium : 
New England coast; Europe. 

4. Oladoga&pto Allman. Colony usually branched; hydrocladia 
not branched; gonangia borne on the stem at the base of the hydrocladia 
and protected by special branchlets armed with nematophores : 15 
American species. 

0. flexilis Verrill (Fig. 182). Colony up to 20 cm. long and slender; 
hydrotheca long and cylindrical, lying close to the hydrocladium; pro- 
tecting branchlets of the gonangia branched like deer's horns: in moder- 
ately deep water along the Atlantic coast; common. 


Trophosome: either a branched or simple colony on which are bell- 
shaped and usually stalked hydrothecae; hypostome trumpet-shaped. 
Gonosome: gonangium large, the blastostyle producing planulae and 
never free medusae: about 33 genera. 

Key to the genera of Campanulariidae here described: 

Ox Hydrotheca rudimentary, the hydranth not being entirely retracted 

into it 1. Halecium 

OfHydrotheca not rudimentary. 
&i Blastostyle does not project from the gonangium. 
c, Stem not completely annulated. 

dj Gonangium without acrocyst, colony not parasitic 2. Campantjlakia 

d» Gonangium with acrocyst ; colony parasitic on other hydroids, etc. 

3. Calyokixa 

Ct Stem completely annulated 4. Opebculabklla 

6, Blastostyle projects from the gonangium 5. Gonothybba 

1. Hausotuk Oken. Branching colonies with creeping hydrorhiza; 
the hydrothecae are more or less rudimentary, being shallow and 
disc-like or funnel-shaped, the margin often with a circle of dots, 
into which the hydranths can be only partially retracted: numerous 

H. halecinum (L.) (Fig. 183). Colony 10 to 20 cm. high, rigid; 
hydrothecae alternate on the stem, cylindrical, often annulated; gonan- 
gia appear in a row, the male gonangium slender and club-shaped, the 
female rather irregular in shape with broad distal end and a terminal 
aperture: New Jersey to Labrador; in shallow water; Puget Sound to 
Alaska; Europe. 

2. Oampavulabxa Lamouroux. Colony either branched or simple, 
with bell-shaped hydrothecae, which are without operculum, and with 
or without marginal teeth: many species. 


Key to the species of Campanularia here described: 
«i Colony not branched, the hydrantb* rising •eparatoly from hydrorhixa. 

6, Marjrin of aperture of hydrotheea not toothed C. POTKBTDK 

6, Marjrin toothed. 

o, Teeth square at top C. HXKOTO 

o, Teeth very shallow, the margin being sinuous C. VOlUbeus 

a. Colony branched. 
61 Colony large, over 10 cm. high. 

c, Margin of aperture toothed C. VUJT101LLATA 

Ot Margin of aperture not toothed C. amphora 

ha Colony small, wider 3 cm. high CnxXTJOSa 

0. potertnm (Agassiz). Colony unbranched, with the hyd ninth s at 
the end of long, completely annotated stalks, which rise separately from 
the hydrorhiza ; aperture of hydrotheea not toothed ; 
hydranth with 24 tentacles; gonangia slender and ovate, 
rising from the hydrorhiza: Vineyard Sound to Labrador; 
low-water mark to 30 fathoms, common on seaweed; 

0. hinckai Alder (Fig. 184). Colony onbranched, the 
hydranthB at the end of long and partially annulated 
stalks which ride separately from the bydrorbiza; aper- 
ture of hydrotheea with 12 square-topped teeth; gonangia 
on short stalks and annotated: from Vineyard Sound to camecnu- 
Maine, on stones and shells; southern California; Europe. 'SumSay)! 1 

0. volubilis (L.). Colony unbranched, the bydranths 
at the end of long completely annulated stalks which rise separately 
from the bydrorbiza; aperture of hydrotheea with 
10 shallow- rounded teeth; gonangia rise from the 
hydrorbiza: from Vineyard Sound to Greenland; 
low-water mark to 100 fathoms; common; Pacific 
coast; Europe. 

0. Tertitillata (L.). Colony branched, attain- 
ing a height of 12 cm. ; bydrothecae with a toothed 
aperture borne on long, partially annotated stalks 
which form whorls around the stem : Long Island 
Sound to Maine, in 4 to 45 fathoms; Alaska; 

C. amphora (Agassiz). Colony branched, 

RtlW- Campomutarta attaining a height of 15 cm.; bydrothecae with 

untoothed aperture and with a swollen stalk; 

hydranth with 30 tentacles ; gonangia truncate : from Long Island Sound 

to Gulf of St. Lawrence; common. 

0. flexuosa (Hincks) (Fig. 185). Colony 25 mm. high, branched 
irregularly; stem annulated near the base of the branches; bydrothecae 


with untoothed aperture and with annulled stalks; gonangia large: 
Long Island Sound to Labrador, on piles, etc, abundant towards the 
north; Europe. 

3. OlXTOZLLA Hincks. Hydrorhiza parasitic on other hydroids, 
Bryoioa, etc., and sending forth short simulated stalks bearing elongate 
eylindrical hydrothecae which have opercula; gonangium oval, rising 
from the hydrorhiza and bearing a globular acrocyst. 

0. syringa (L.). Hydrotheca longer than 
its stalk: Long Island sound to Maine; com- 
mon; Pacific coast; Europe. 

4. OramcuXAWXA. Hincks. Stem annu- 
latod throughout and sparsely branched or 
unbrancbed; hydrotheca with operculum; 
gonangium with acrocyst. 

O. lacerate Hincks. Hydrothecae with 
short stalks ; segments of operculum very long 
and slender: Long Island Sound to Maine, on 
docks, etc. 

5. Gqmothteia Allman. Stem erect, ir- 
regularly branched, more or less simulated; 
hydrotheca bell-shaped, with toothed margin; 
the blastostyle produces fixed, medusiform 
sporosacs with radial canals and tentacles, which 
project ont of the gonangia but are not free- 

Fig. 188 — ttmoihyreo swimming: several species. 

Jo.<M (Hargitt). 1otwi1 AUmall (Fig 186) stem 1Q to 

15 mm. high; from the mature gonangium project 3 to 5 sporosacs: on 
shells, stones, etc., in shallow water from Long Island Sonnd to Maine; 

O. clarki Torrey. Similar to the above but without radial canals in 
the sporosacs; hydrotheca deep, with margin having 10 square-topped or 
bicuspid teeth: Pacific Coast from California to Alaska; often common 
in shallow water. 

Family 4. EUOOPIDAE. 

Trophosome: colonial, either branched or simple; hydrotheca bell- 
shaped and stalked, the margin of the aperture either toothed or not; 
gonangia large and usually in the axils of the branches. Gonosome: 
gonangium large, the blastostyle producing free medusae with lithocysts 
and usually without ocelli, with 4 radial canals, beneath which on the 
subumbrella are the gonads, there being as many gonads as radial 
canals : about 34 g 


Key to the genera of Eucopidae here described (bydroid form well 
known in Obelia and Clytia alone) : 

a, Manubrium of medusa short: hydroid mostly a branching colony. 
o,Medusa Bat and disc-like ; hydroid a branching colony ; hydrotheca often 

without a toothed margin 1. OBELU 

6, Medusa bell-shaped or hemispherical. 
c, Medusa with no more than 16 marginal tentacles. 
d, Medusa without cirri at the base of the tentacles; hydroid not or very 

sparsely branched ; hydrotheca with toothed martin 2. Clttia 

d, Medusa with 4 or more tentacles, each of which has 2 basal cirri. 

c, Medusa with more than 16 tentacles. 

a\OraJ lobes frilled 8. TUBOFBia 

df Oral lobes not frilled 5. Oosanu 

a. Manubrium of medusa very long: hydroid mostly unknown. 

e, Tentacles 4. 6. Btmiu 

e. Tentacles of adult numerous T. TiMA 

1. Obslia Psron and Leeueur. Hydroid colony usually branched, 
the stem with annulations at the base of the branches and the; 
hydrotheca often with ,, un toothed margin; gonangium 

with a small terminal £mET a a P ertur *> usually surrounded by 

a collar or neck; me- %Kr linHa more or ' eBS disc-shaped, X 

to 6 mm. in diameter, jf \. with 12 or more marginal 

tentacles and 8 (A IniVaWB lithoeysts, often swim- 

ming with everted ^^.W J^^jL De ^ : numerous species, 

; c. 

the medusae of which can often not be distinguished from one 

0. commisanralis McCrady. Colony tree-like with long central trunk, 

15 to 20 cm. high, sparsely branched, the side branches springing out at 
right angles; hydrotheca not toothed; gonangia elongate; medusa with 

16 or more tentacles: on docks, algae, etc., from South Carolina to Bay 
of Fundy; common; California. 

O. dichotoma (L.) (Fig. 187). Colony rather small with a deep 
brown stem and a general tree-like appearance; branches zigzag; hydro- 
theca elongate without toothed margin; gonangia long and conical; 


medusa with 16 tentacles lit liberation : from South Carolina northwards ; 

common on stones, seaweed, etc.; Pacific coast; Europe. 

0. geniculate (L.) (Fig. 188). Colony not more than 30 mm. high 

and consisting usually of a single zigzag stem bearing 

alternate hydranths on short annotated stalks; gonan- 

gia borne in the angles of these stalks; medusa with 

24 tentacles at liberation : on docks, fucus, etc., from 

Long Island to Labrador; 

very common; California; 


0. golatinosa (Pallas). 

Colony tree-like, profusely 

branching and very large, 

Fig- 188 being sometimes 25 cm. high 

Ohelia (7«i*«iioJn 

and zigzag branches; hydro- 

thecae small, with toothed margin; gonangia small; medusa with 16 
tentacles at time of liberation : on docks, seaweed, etc., in shallow water 
from New Jersey to Massachusetts Bay; very common; Puget Sound; 

2. OlyTU Lamourouz. Hydroid colony sparsely branched or not 
at all, the hydranths being at the end of a usually long, more or lesa 
simulated stalk which rises from the hydrorhiza; hydrotheca with 
toothed margin; gonangia often annulated, on the hydrorhiza or the 
stem; medusa with 16 tentacles and 16 lithocysts: S species. 

0. bicophora Agassiz (Fig. 189). Colony about 10 mm. high; medusa 
5 mm. in diameter, hemispherical when liberated but later becoming 
more flattened; gonads brown, manubrium 
short, with 4 small oral lobes : from South 
Carolina to Arctic Ocean, on fucus, docks, 
etc., in shallow water; often common. 

3. Tubofsh Agassiz. Hydroid form un- 
known; medusa hemispherical; marginal ten- 
tacles very numerous in adult; manubrium 
short with frilled mouth opening; 8 lithocysts 
above each of which is an ocellus: 6 species. 
T. diademata Agassiz (Fig. 190). Medusa 
15 mm. in diameter, with sloping sides; manubrium with 4 prominent 
lips: New England coast; often abundant. 

4. Euoheimwa McCrady. Hydroid form unknown; medusa hemi- 
spherical; tentacles each with a pair of lateral cirri at its base: 6 


B. duodecimal!! A. Agassis (Fig. 191). Tentacles 4, each with a pair 
of cirri at its base; diameter 2.5 mm.; manubrium very short: Cape Cod 
to Florida; often common. 

5. Oc&ajtli Peron and Lesneur. Hydroid form mostly unknown; 
medusa hemispherical with 16 or more tentacles; lithocysts also numer- 
ous in adults, 2 being between each two marginal tentacles; gonads 

colored and borne along the outer half of radial canals: manubrium 
with 4 everted oral lobes: 6 species. 

0. 1»«(pHil« A. Agassiz (Fig. 192). Gonads brownish or pink or 
green; tentacles 20 or more; diameter 20 mm.: from Bay of Fundy to 
Florida; often common. 

6. Burma MeCrady. Hydroid form unknown in most species; 
medusa bell-shaped with 4 or more tentacles and a very long manubrium 
extending far out of the bell; 8 lithocysts: 12 species. 

E. mira McCr. (Fig. 193). Medusa 2 cm. 
in diameter and half as higb, with gonads ex- 
tending along almost the entire length of radial 
canals; tentacles 4 in number and very long, 
the base swollen and colored green : Florida to 
New England; very common at Woods Hole in 

7. TntA Eschscholtz. Hydroid form minute; n 194 
medusa hemispherical with a long manubrium 
sometimes extending out of the bell, at the end 
of which are 4 frilled projections surrounding the 
mouth; tentacles numerous; gonads extending the length of the radial 
canals and the manubrium: 5 species. 

T. formosa Agassis (Fig. 104). Diameter 4 to 8 em.; gonads and 
oral lobes milk white: New England coast; often common, especially in 
the spring. 


Family 5. £QUOKELDAE. 
Trophosomc : mostly unknown. Gonosome: medusa often of large 
size and more or less disc-shaped, with from 8 to 100 radial canals; 
gonads usually ribbon-like; 8 or more Hthocysts; 8 or more marginal 
tentacles: about 7 genera. 

Key to the genera of ^Squoreidae here described : 
a, Manubrium short. 

6, Radial canals 8 to 20 1. Halopbis 

b. Radial canals 16 to 100 2. JCqcorea 

a, Manubrium large and long 3. Ztqodacttla 

1. Halopsib A. Agassis. Medusa disc-like in adult and hemispher- 
ical in youth; radial canals 12 to 20 in 4 groups; marginal Hthocysts, 
_ tentacles and cirri numerous ; 

manubrium short with 4 oral 
lobes: 1 species. 

H. ocellata A. Ag. Di- 
ameter 7 cm.: New England 
coast; rare. 

2. jEauoasA Peron and 
Fig. ns-jiiuorea t«m* (Majer). Lesueur. Hydroid form mi- 

nute and mostly unknown; 
medusa disc-shaped or hemispherical, with a short, wide manubrium 
and numerous radial canals, lithocysts, and tentacles: 10 species. 

A. (Rhegmatodes A. Agassiz) tennis 
A. Ag. (Fig. 195). Radial canals 20 to 
40 with an equal number of gonads; ten- 
tacles numerous, long and slender, with a 
spur above the base of each; diameter 3 
to 10 cm.: Vineyard and Long Island 
Sounds; very irregular in its occurrence. 
A. albida (A. Ag.) Radial canals 
and tentacles 80 or more in number; 
above each tentacle is a spur; diameter 7 
cm. : New England coast. 

3. Zyoodaottla Brandt. Hydroid 
form unknown; medusa arched and with 

a large sac-like manubrium with exten- Fig- too— Zygoiiac.tvia grado*- 
eive frilled oral lobes extending beyond °° " 7e> 

the velum; subumbrella with rows of warts between the radial canals: 
1 species. 

Z. groBnlandlca (Paron and Lesueur) (Fig. 196). The largest Amer- 
ican hydromednsan, measuring 12 cm, or more in diameter; radial email 


and tentacles 80 to 100 in number: Greenland to North Carolina, the 
southern variety being pink. 


Trophosome: unknown in most genera. Gonosome: medusa ocel- 
late and without lithocysts, with a short manubrium and usually 4 to 8 
radial canals: about 14 genera. 

1. Mzlxokbtitm Oken. Hydroid form minute; medusa bell-shaped; 
8 radial canals and numerous long tentacles with ocelli at their base: 
4 species. 

M. campanula Agassiz. Color of medusa light ochre, tentacles and 
gonads darker; manubrium short with convoluted lobes; height and 

diameter 2 cm.: Cape Cod to Greenland, 
often abundant; Europe. 

2. Laodioza Lesson (Lafcea Lamou- 
rouz). Hydroid an unbranched colony with 
Bl* i97-^gio«foM eaiaarata a filiform hydrorhiza; hydrothecae tubular; 

gonangia oblong, often forming encrusting 
masses around the stem; medusa hemispherical when young, but flatter 
as adult, with 4 radial canals and numerous tentacles, with basal cirri 
and ocelli: 6 species. 

L. calcarata A. Agassiz (Fig. 197). Hydroid form usually parasitic 
on sertularians ; medusa transparent with 2 tentacles at birth, but many 
later, which are quite rigid; manubrium short, with fluted sides; diam- 
eter 25 mm.: Massachusetts Bay to Florida. 


Trophosome: wanting in most forms, so far as known; where pres- 
ent, of minute size and allied apparently to the Tubuktriae. Gonosome: 
free medusae, usually rather large, more or less bell-shaped, with a 
velum and 4, 6, or 8 radial canals, along which on the subumbrella are 
the gonads; manubrium usually long, often extending beyond the velum; 
tentacles often very long and sometimes springing from the exumbrella; 
lithocysts with concretions of entodermal origin and either freely pro- 
jecting or enclosed in pockets; development apparently direct in most 
cases, without alternation of generations, the animals being essentially 
open-ocean animate, most of which are not bound to the shores by a 
hydroid generation, and where the latter is present it is apparently in a 
degenerate condition: 5 families and 80 species. 


Key to the families of Traehomedusae here described: 

a. Radial canals 4 or 6. 

6, Gonads not plate-like, usually undulating 1. Petasidak 

6, Gonads plate-like 3. Gkbyoniidae 

a, Radial canal* 8 2. Aqcacrioab 

Family 1. PETA8IDAE. 

Trophosome : minute and apparently mdimentary, so far as known, 
probably wanting in many cases. Gonosome : medusa with 4 or 6 radial 
canals; gonads elongate and much folded or sac-like; tentacles either 

Flf. 198— AHUMMWt nw'bcM A, hjdrold (Perkins) : B, meflnsn (Hajer). 

with or without a pad-like cluster of modified nettle cells near the distal 
end for purposes of adhesion; manubrium short: about 14 genera. 

1. GtffXomnroiV* A. Agassiz. Trophosome: minute, so far as known. 
Gonosome: medusa with 4 radial canals, along the entire length of which 
the sinuous gonads extend; adhesive pad near the extremity of each 
tentacle; numerous ItOiocysts present f" '7 species; cosmopolitan. 

O. mnrbichi Mayer (Fig. 1 JIM) . Trophosome: solitary hydra-like 
individuals 1 mm. high with 4 tentacles. Gonosome: medusa 20 mm. in 
diameter and half as high ; marginal tentacles from 16 to 80, long and 
stiff and green at the base; gonads brown; manubrium short with 4 
frilled oral lobes: Vineyard and Long Island Sounds. 

G. verteiis A. Ag. Similar to the above, but higher than wide: 
Pacific coast from Washington to Alaska. 

2. Micbohtdba) Potts. Trophosome: a minute hydroid without 
tentacles and solitary, but multiplying by lateral budding. Gonosome: a 

• See 'The Development at Gonlonema murbacbti," by H. R Perkins, Proc. Acad. 
Nat Bel., 1902, p. T60. 

t See "On the Medusa of Mlcrobjdra," etc., by Edward Potts, Quart Jour. kttc. 
Sci., Vol. 50, p. 023, 1S00. "Microbjdra la 1907," Proc. Delaware Co. Inst, Vol. S, p. 
SU. 1908. 



medusa which buds from the bydroid, bell-shaped, with 4 radial canals 
and 8 tentacles: 1 species, in fresh water. 

M. ryderl Potts (Fig. 199). Hydroid cylindrical, with a crown of 
nematoeysts around the mouth, .5 mm. 
long, often branched near the base 
into two equal individuals; medusa .3 
mm. high and .4 mm. wide at birth; 
no sense organs or gonads observed: 
on stones in rapid streams in Phila- 
delphia; Germany. 

3. OzAmSAODUA Lankester 
[Limnocodium Allman). Trophosome: 
minute, without tentacles. Gonosome: 
disc-like medusa with 4 radial canals; 
tentacles numerous, of several dif- 
ferent lengths; lithocysts numerous; 
manubrium long: 2 species; distribu- 
tion world-wide. 

0. sowerti* Lank. (Fig. 200). 
Diameter about 12 mm. ; gonads 4, 

suspended from the radial canals, greenish in color; oral lobes, large, 
crennlated, greenish; bell translucent 
with a faint bluish tint; 4 long, about 
28 shorter and 192 shortest tentacles: 
in a fresh-water aquarium in Wash- 
ington containing tropical water lilies; 
also in similar places in London, Mu- 
nich, and Lyons; probably introduced 
from South America. 


Trophosome: wanting. Gonosome: 
medusa with 8 radial canals, free 
lithocysts and gonads in berry-like 
masses and numerous tentacles: 5 
Key to the genera of Aglauridae here described: 
o, Gonads 8. 

i. Gonads borne on manubrium 1. Aolauka 

6, Gonads borne on radial canals 2. Aolantha 


1. Aolauka Peron and Lesueur. Gonads 8, on manubrium; 8 litho- 
eysts: 1 species. 

A. hemistoma Pit. and Lea. Medusa cylindrical or octagonal, 4 mm. 
high, truncated above, transparent; radial canals 
8; tentacles numerous, very short; 18 finger-like 
gonads suspended from the manubrium: cosmo- 

2. Aolamtha Haeckel. Gonads 8, on subum- 
brella: 3 species. 

A. digitalis (0. F. Miiller) (Fig. 201). Me- 
dusa elongate, miter-shaped, 30 mm. high and 15 
mm. vide, with 8 radial canals, pinkish and trans- 
parent; tentacles numerous; gonads elongate and 
suspended from the upper end of the subumbrella; 
Big. 201 mouth with 4 everted lips: North Atlantic; often 

*0k»th«*?JloMi common on the New England coast. 

3. Psxba McCrady. But 2 gonads present, 
which are thick and elongate and on opposite sides of the umbrella; 
8 lithoeysts; numerous tentacles: 1 species. 

P. incolorata MeCr. Bell thimble-shaped and colorless; gonads 
yellowish; tentacles long and brittle and easily broken off; 3 mm. high 
and half as wide: coasts of North and South Carolina; rare. 


Trophosome: wanting. Gonosome: medusa 
hemispherical; manubrium very long; 6 or 8 en- 
closed lithoeysts; radial canals 4 or 6; gonads plate- 
like : 2 genera. 

Ltxiopx Lesson. Manubrium extending far 
beyond the velum and with a square mouth; 4 
radial canals, between each pair of which are 1 
to 3 centripetal (t. e., extending from the circular 
canal upwards) canals, and 4 to 12 tentacles: 20 

L. exigna (Quoy and Gaimard) (Fur. 202). 
Bell hemispherical, 20 mm. wide: Gulf Stream; 
Mediterranean ; occasionally on the New England Flf - ™ 

Ltoope exigna 
coast. (jfajer). 


Trophosome: wanting, so far as known, development being direct, 
the animals living in the open ocean. Gonosome: medusa with lobed 


margin; tentacles stiff and extending from the exumbrella; gonads on the 
subumbrella; gastrovascular cavity a wide central space, either circular 
in outline or with radial pouches or canals extending outwards; ring 
canal follows the marginal lobes but is often absent; lithocysts free 
and often projecting, with entodermal concretions; a thickened ecto- 
dermal ring is at the edge of the umbrella with prolongations called 
peronia extending to the base of the tentacles, and often others also, 
called otoporpae, extending upwards from the base of the lithocysts: 
2 families and 50 species, of which a few are found along our coast. 

Family ^SGINIDAE. 

Radial pouches of gastrovascular space present: 11 genera. 

1. Ctoootahtha Haeckel. Tentacles, marginal lobes, and radial 
pouches 8; otoporpae present; the larvae live parasitically in the bell 
of the mother or some other medusa where they bud off new larvae from 
a stolon-like prolongation of the apical 

end of the umbrella: 5 species. 

0. octonaria McCrady (Fig. 203). 
Diameter 7 nun. ; manubrium cone-shaped 
with 4 lips: common at Beaufort, North 
Carolina, the larvae infesting Turritopsia 
nutricula; cosmopolitan. «* ™*- 4 ffi2SS^ °° UmaHa 

2. Cuviha Eschscholtz. Tentacles 

and radial canals 9 to 24; the larvae live parasitically in the bell of the 
mother or some other medusa: 10 species. 

C. lativentris Gegenbaur. Medusa fiat, transparent, about 16 mm. in 
diameter; tentacles, marginal lobes, and stomach pouches 10 to 12; litho- 
cysts on each lobe 4: Atlantic Ocean and Mediterranean Sea. 


Free-swimming, colonial Hydromedusae. The individuals forming a 
colony are in a high degree polymorphic, there being several orders of 
individuals all of which are in communication with one another by means 
of the common gastrovascular space. Each order performs a distinct 
function in the colony, the division of labor being similar to that which 
obtains among the various organs of the body of one of the higher animals. 
Two general types of structure are met with among the Siphonophora. In 
one (Fig. 204) the various individuals bud off from a long axial tube, 

• See "The Sipbonopborae of the Challenger/' by B. Haeckel, Challenger 
Reports, VoL 28, 1888. 



the upper end of which is expanded to form a float called the pneumato- 
phore which contains air or a gas and serves to keep the colony right 
side up in the water: in the other type (Fig. 205) no such axial tube 
is present, the various individuals budding off from the under side of 

the enormously enlarged float. By far the greater 
number of siphonophores are of the first type. The 
individuals budding off from the axis immediately 
back of the pneumatophore are swimming individ- 
uals or nectophores; these are present in pairs, and 
each has the form of a hydrozoan medusa without 
the manubrium. Following the nectophores at in- 
tervals on the axis are similar groups of individuals, 
each group consisting usually of (1) the bract, a 
flat, scale-like protective individual; (2) a club- 
shaped palp; (3) a nutritive individual or gastro- 
zooid, which is the mouth and stomach of the colony ; 
(4) a long tentacle with nematocysts; (5) repro- 
ductive individuals or gonozooids, which are usually 
unisexual. A colony of this kind swims about slowly 
in the sea and may be several feet in length and 
contain thousands of individuals. A modification of 
this type is seen in the deep-sea siphonophores of 
the genera Stephalia and Rhodalia, in which the 
pneumatophore is very large and the axis short and 
thick. In Stephalia a mouth is present at the terminal end of the axis, 
which forms the chief gastrozooid: the axis is thus in this case directly 
comparable with the manubrium of a medusa, 
of which the pneumatophore would be the bell. 
In Rhodalia the axis has lost its character of a 
gastrozooid, not having la mouth at the lower 
end. These animals are probably primitive 
siphonophores and seem to indicate the deriva- 
tion of the group from a medusan instead of 
from a mixed hydroid and medusan stock. They 
also form a connecting link between the two 
general types of Siphonophora, those with an 
axial tube and those which have none. 

Siphonophores are essentially pelagic animals, although some forms 
are found in deep water. They belong to the open ocean, especially of 
the warmer parts of the world, and are among the most beautiful and 
conspicuous animals found there. The order contains about 250 species, 
grouped in 4 suborders. 

Biff. 204— Diagram 
of a slphonophore (Mc- 
Murrlch). l t pneuma- 
tophore ; 2, necto- 
phore; 3, bract; 4, 
gonozoold; 5, gastro- 
looid ; 6, club ; 7, ten- 

Fig. 205 

Diagram of a Porpita 
(Delage et Herouard). 


Key to the suborders of Siphonophora: 

Ox Pneumatophore present. 
6, Pneumatophore very large ; nectophores absent 

Cj Pneumatophore a disc, with a large central gastrosooid. . . .1. Disookkctas 
c, Pneumatophore more or lees cylindrical, without a large central gas- 
trosooid 2. Cystoihdotae 

6, Pneumatophore usually small ; nectophores present ; colony usually 

elongate 3. Physonectae 

a, Pneumatophore absent ; nectophores very large ; colony swimming rapidly. 

4. Calyoonectab 

Suborder 1. DISCONECTAE. 

Siphonophores with a very large disc-like pneumatophore and with- 
out swimming individuals (Fig. 205). The pneumatophore has a com- 
plex structure; it contains a number of air chambers and beneath its 
center is a single large trunk which bears the principal mouth and 
stomach of the colony. Surrounding the trunk are small reproductive 
individuals which bear the gonads, and surrounding them near the rim 
of the disc are long dactylozooids or tentacles armed with nemotocysts. 
The whole colony bears a striking resemblance to a medusa: 36 species, 
grouped in 2 families. 


Pneumatophore a circular or elliptical disc without marginal inden- 
tations: about 30 species. 

1. Velklla Bosc. Disc elliptical and very flat and with an ele- 
vated ridge passing diagonally across it, which acts as a sail as the 
animal floats on the surface of the water: 13 


V. muticA Bosc (Fig. 206). Length of 
disc 4 cm., breadth 2 cm.: along the South 
Atlantic coast, occasionally off New England. 

2. Pobvxta Lamarck. Disc circular, and Fig. 206— Velella mutica 

(from Lankeater). 

without the sail: 8 species. 

P. linnffiana Lesson (Fig. 205). Diameter of disc 3 to 5 cm.: along 
the South Atlantic coast, occasionally off New England. 

Suborder 2. CYSTONECTAE. 

Siphonophores with a very large pneumatophore from the under side 
of which project nutritive individuals, no large central trunk and no 
swimming individuals being present. The colony floats on the surface 
of the water, often carried by currents and the wind long distances, 
and can sink beneath the surface by compressing the pneumatophore 

• Bee *Tbe Porpitldae and Velellidae," by A. Agarals, Mem. Mos. Comp. Zool., 
VOL 8, 1888. 


and driving out the air or gas through a pore in its upper side. In 
order to rise to the surface again it fills the pneumatophore with a self- 
generated gas. The suborder contains 30 species grouped in 5 families. 
With the above-described characters : 4 genera and 10 species. 

Fstsalu. Lamarck, Pneumatophore 
with a dorsal crest with transverse septa: 
4 species. 

P. pelagica Bose. Portuguese man-of- 
war (Fig. 207). Pneumatophore up to 12 
^y cm. long, pear-shaped with iridescent col- 

ors; tentacles long, sometimes stretching 
10 or 15 meters, and with powerful stinging 
organs: in the Gulf Stream from Florida 
to Vineyard Sound and occasionally to the 
Bay of Fundy; often common. 

Subobdeb3. PHYSONECTAE. 

rnytaua veiagioa jT Siphonophores with a pneumatophore 

( a enteo. ft yntiv & long trunk or axis from which bud 

off nectophores and successive similar 
groups of individuals, each group containing usually a bract, a gastro- 
Eooid, a palp, a tentacle, and a gonozooid: 9 families and about 75 


Two longitudinal rows of alternating nectophores; trunk long, bear- 
ing numerous groups of individuals: 30 species. 

Outuxita Quoy and Gaimard [Nanomia A. Agassis). Four to 6 
nectophores in each row; individual groups not all of the same impor- 
tance, there being secondary groups lacking the gastrozooids between 
the principal groups: several species. 

O. cars (A. Ag.). Length of colony about 11 cm.: Newport and 
Massachusetts Bay. 

Subobdee 4. CALYCONECTAE. 

Siphonophores with very large swimming individuals (nectophores) 
and without pneumatophore or palps, the individual groups consisting 
each of a nutritive and one or more reproductive individuals, a covering 
bract, and a short tentacle. The colony swims rapidly, in contrast to 
most siphonophores, being partly sustained by a drop of colored oil 
present in each nectophore: 5 families and 05 species. 

8CYPB0Z0A 125 


Two neetophores present : 10 genera and about 35 species. 

Dmni Cuvier. Nectopbores conical and very large; the remain- 
der of colony can be retracted into a groove in the nectophores and ia 
constantly being shortened by the breaking off of 
the terminal and oldest groups of individuals, each 
group (which is called an Eudoxia) thus separated 
leading an independent life and becoming sexually 
mature: 6 species. 

D. bipartite Costa (Fig. 208). Total length 30 
mm.; length of the nectophores 10 mm.; body trans- 
parent: tropical and subtropical Atlantic; Mediter- 
ranean; occasionally on New England coast; often 
very common. 

Class 2. SOTFHOZOA. (Sctpeomedusae.) 
These animals have usually an alternation of 
generations, in a few (Pelagia), however, the medu- 
soid generation and in others {Lucernaria) the 
bydroid alone being present. The medusoid plays Fig _ 2 iis 

a much more conspicuous part than the bydroid. wphtmbtpartita 
The latter is a small, usually non-colonial animal 
called the scyphistoma, which is less than a centimeter in height and 
resembles the fresh-water Hydra in appearance (Fig. 217, A). It differs 
from Hydra, however, in that the aboral end is fixed to the bottom in a 
cnp formed of the perisarc, in the possession of four longitudinal folds 
of the entoderm called mesenteries which project into the gastrovascular 
space and of an ectodermal gullet. The scyphistoma is an asexual 
animal and reproduces by budding exclusively. New scyphistomas may 
be produced by a process of lateral budding from stolons sent off from 
the foot. The medusoid generation is produced by a process of terminal 
budding called strobilation (Fig. 217, B). The scyphistoma grows in 
height and a series of constrictions appear which divide it into a number 
of discs. Each disc is called an ephyra (Fig. 217, C) and is a young 
medusa or jellyfish, which on becoming free grows in time to be a sexual 

The medusa which is thus produced is often a large animal ; Cyanea 
may be two meters and more in diameter with tentacles thirty-five 
meters or more long. It is called acraspedote because the velum, which 
is so characteristic of the craspedote Hydromedwae, is wanting or 
rudimentary. The periphery of the bell is lobed or scalloped and may 
or may not have tentacles. The manubrium is sometimes very long and 


large and extensively branched and in the Bhizoatomata the mouth is 
closed by the coalescence of its sides, small pores remaining through 
which nutriment is taken in. The gastrovascular space is complex in 
form and usually consists of four radial pouches forming a large space 
in the center of the animal and additional radial canals which often 
branch and may be joined at their outer ends by a circular canal. 

The gonads are four in number and often brightly colored; they 
are specialized portions of the entoderm and appear in the interradii of 
the gastrovascular space. In many species four large pockets, called the 
subgenital pockets (Fig. 216, S) and probably respiratory in function, 
are present in the subumbrella directly beneath the four gonads. Beside 
each gonad are usually a number of cylindrical mesenterial filaments, 
armed with nettle organs. 

The finer structure of the Scyphozoa is essentially like that of the 
Hydrozoa. The mesoglea is different, however, in that it is much firmer 
and usually cellular. The sense organs are also different, being perhaps 
modified tentacles, and are called tentaculocysts or rhopalia. 

The Scyphozoa are all marine and among the most familiar animals 
along our shores. The class contains 5 orders and about 180 species. 

Key to the orders of Scyphozoa: 

<h Body stalked and sessile, there being no medusa stage. . . .1. Staubohedusae 
Of Free-swimming medusae present. 

& t Medusa with distinct constriction about its middle 2. Coronatae 

b t No such constriction present. 

C| Tentacles present either on the margin or the subumbrella. 
(Ji Medusa cuboidal in shape with 4 long marginal tentacles or groups of 

them 3. Cubomedusae 

da Medusa with 8 or more tentacles on margin or subumbrella. 

4. Sebiaostomeae 
o% No tentacles on margin or subumbrella 5. Rhizostomae 


Body conical in shape with aboral surface usually drawn out to 

form a stalk by which it is temporarily attached, representing a sexual 

scyphistoma ; margin with 8 prominent lobes, each with a cluster of short 

knobbed tentacles; without sensory organs but often with marginal 

adhesive pads (marginal anchors) in the angles between the lobes: 26 

species and 2 families, the animals usually attached to seaweed in 

shallow water. 


Margin with 8 lobes, each with numerous knobbed tentacles; animal 
attaches itself temporarily to algae, along which it crawls: 5 genera. 

• See "Lucernarlae and Their Allies," etc., by H. J. Clark, Smithsonian Contrtb. 
to Knowledge, Vol. 23, 1878. 

8CTPH0Z0A 127 

Key to the genera of Lucentariidae here described : 

a, Adhesive pods absent 1. LtTCISSABlA 

o, Adhesive pads present 

6, Sulk quadrate 2. Halicxystus 

6, Stalk cylindrical 3. Haumoctathcs 

!. LvciBVAKU 0. F. Miiller. Marginal adhesive pads absent; stalk 
cylindrical: 8 species, 1 American. 

L. quadricoraia Mull. Height 7 cm.; diameter 5 cm.; color green, 
gray, or reddish; tentacles on each lobe 100 or more: Gape Cod to 
Greenland; Europe. 

2. Haxjoltbtvs Clark. Eight 
marginal adhesive pads between 
the lobes; stalk quadrate; 6 spe- 
cies, 2 American. 

E. auricula Clark (Fig. 209). 
Height and diameter 3 cm.; color 
variable; tentacles on each lobe 
100 or more: Cape Cod to Green- 
land; Europe ; Alaska. 

H. salpinx Clark. Height 20 
mm; diameter 25 nun.; tentacles 
slender, about 70 on each lobe; 
marginal pads very large and as 

long m tb. to-tod-i C.p. Cod to ^ „^atm>m -M. HM. 
Greenland; Adriatic Sea. 

3. Hat.tmooyathpb Clark. Marginal adhesive pads present; 4 
gastrogenital pockets present in Bubnmbrella wall of the gastro vascular 
pooches; stalk cylindrical: 2 species. 

H. lagsna (Haeckel). Height 3 cm.; diameter 7 nun.; tentacles on 
each lobe 70: Cape Cod to Greenland; rare; Europe. 

Obdeb 2. 0OBONATAE. 

Mednsa with a constriction about its middle; margin in most cases 
with 16 lobes, long tentacles and rhopalia: 5 families and 27 species, 
which are usually found in the open ocean. 


Marginal lobes 16; tentacles 4 or more; rhopalia 4: 4 genera and 
8 species. 

Pkhipktxla. Steenstrup. Twelve tentacles; body conical; 4 deep 
mbgenital pockets (funnels); gonads horseshoe-shaped: 3 species. 


P. hyadnthina Steen. (Fig. 210). Medusa about 8 cm. high and 4 
, wide; color reddish: Greenland; Gulf Stream; cosmopolitan. 

Fig. 210 Fig. 211 

Fig. 210— Perlpkylla KyaoliUMna (Mayer). Fig. 211 - XautitHoB punctata (Mayer). 

Family 2. EPHYBOP8IDAE. 

Usually 16 marginal lobes; 9 rhopalia and S or more tentacles: 
3 genera and 11 species. 

1. Hausixhob Kolliker. Gonads 8; tentacles 8; marginal lobes 16; 
ectoderm of bell with clusters of small crystals: 6 species. 

N. punctata K611. (Fig. 211). Medusa 10 mm. broad and 4 mm. 
high; marginal tentacles stiff: cosmopolitan; Gulf Stream; common. 

S. LnmoHZ Esehscholts. Similar to 
Nausithoi but with sac-like gastric pouches: 
2 species. 

L. ungniculata Eschs. (Fig. 212). 
Medusa cylindrical or thimble-shaped, 13 
mm. high and 16 mm. wide: Gulf stream; 
often in swarms. 


Body more or less cuboids! in form, 
with a single interradial tentacle or a 
group of tentacles at each of the 4 corners, 
the bases of which are in most forms 
expanded to form prominent flattened 
structures called pedalia; rhopalia 4, between the tentacles; 4 wide gas- 
tric canals in which are the plate-like gonads; false velum (velarium) 
present, which together with their energetic swimming movements gives 
the animals the appearance of craspedote medusae: 1 family and about 
16 species. 



With the characters of the order: 6 genera. 

1. Tamo y a F. Muller. Four tentacles, with prominent pedalia; 4 
«lnsters of gastric cirri: 1 species. 

T. haplonema F. Miil. (Fig. 213). Medusa 9 cm. high and 5 cm. in 
diameter; exumbrella covered with wart-like 
clusters of nematocysts : Long Island Sound 
to West Indies. 

3. OsXMHAXKUt Agassis. Four groups 
of about S tentacles each, each group ex- 
tending from the fingers of a palmate peda- 
lium; finger-like sacs extending into the cav- 
ity of the bell from near the base of the 
manubrium: 4 species. 

0. quadnimanufl Ag. Medusa 10 cm. 
high and 14 cm. in diameter: North Caro- 
lina and southwards, often common in 
shallow water. ** 318 -f 1 K£*» ) . topto "*" 


Houth qoadrate, with 4 long, oral lobes, often folded and frilled; 
marginal tentacles hollow, often very long; rhopalia marginal: 3 families. 
Key to the families of Semaostomeat: 

d Very long marginal tentacles 1. Pelaqiidae 

a, No long marginal tentacles. 

ft, Long tentacles on sub umbrella ; no marginals 2. Cyahbidae 

b, Short marginal tentacles 3. Uucabtdai 


Large, brightly colored medusae, disc-like 
or hemispherical in form, with wide, simple, 
radial gastrai pouches and no ring canal, and 
very long oral lobes and marginal tentacles: 
5 genera and 18 species. 

1. Felaoia Peron and Leaueur. Eight ten- 
tacles and 8 rhopalia; 16 marginal lobes; exum- 
brella covered with warts of nettle cells; devel- 
opment direct, no bydroid stage being present: 
Flg.214— PeUgtaeyamtHo ? species. 

(Mayer). p ^^^^ p& , ud j^. (Fig , 2 14). Diam- 

eter 5 cm. ; height 4 cm. : coast of Florida and the Carolines, occasionally 
appearing as far north as New England. 


2. DAOTTLOMETttA Agassiz. Forty marginal tentacles; 8 rhopalia; 
48 marginal lobes: 5 species. 

D. q.uinquecrjTha (Desor). Diameter up to 25 cm.: Long Island 
and Vineyard Sounds to the tropics. 

Famlt 2. CTANEIDAE. 
Large disc-shaped medusae; radial pouches of the gastro vascular 
cavity very wide and ramifying at their distal ends; no ring canal and 
no subgenital pouches: 4 genera, con- 
taining the largest medusae; 6 species. 
Cyamea Perot) and Lesueur. Eight 
groups of very long tentacles which ex- 
tend from the subumbrella; oral lobes 
very long, wide, and voluminous, between 
which and the tentacles are the 4 large 
buncbes of gonads which have evagi- 
natcd from the past ro vascular cavity; 
8 rhopalia in as many marginal indenti- 
ng. 21B-C™« oo^Iteta nt. tionB : 2 8 P ecie8 " 
uUWtl^ aad °- C * PiU,lta ^ Var ' **** P6r - (md 

•&%nr«iTfflaW: L< * {Fig - 215) - Disc nsnally io to m 

cm. in diameter, but specimens 2 m. in 
diameter have been seen with tentacles 40 m. long; color variable, usually 
purplish red or brown ; the largest jellyfish : common from North Carolina 
to Qreenland; a light-brown variety called C. fulva Agassiz occurs in 
Long Island Sound, and a bluish-white variety called C. versicolor Ag. off 
the Carolina coast 

Family 3. ULMARJDAE. 

Radial canals nar- 
row and branching, 
forming a complex sys- 
tem with a circular 
canal joining the distal 
ends : 10 genera and 17 

Avbxlia Peron 
and Lesneur. Oral 
lobes long and rather 
narrow; marginal ten- 
tacles minute; body flat and disc-like; 4 large subgenital pockets; : 
rhopalia in as many marginal indentations: 5 species. 

8CTPE0Z0A 131 

A. atuita (L.) var. flavtdnla Per. and Lea. (Figs. 216 and 217). Dim 
ma; be 30 cm. or more in diameter; color white or bluish with pink 
gonads : very common along the entire Atlantic coast, breeding through- 
out the summer, the scyphis- 
toma stage lasting throughout 
the winter. 


Marginal tentacles absent; 
8 oral lobes very large and much 
branched extend from the cen- 
ter of the subumbrella with 
sacking pores along their edges 
which take the place of a mouth, 
the month being usually obliter- 
ated; oral tentacles border the 
pores : 63 species. 

1. BTOraoran Ag«.U. B „ ><1 „„ I „,,„,„ 
Body hemispherical; the fused 

oral lobes form a thick cylinder at the bottom of which are 8 pairs of 
frilled lobes and a central mouth opening; 8 rhopalia: 1 species. 

8. meleagria Ag. 
(Fig. 218). Diameter 
18 cm.; color of emm- 
brella brown : from 
Florida to North Caro- 
lina and occasionally to 
the coast of New Eng- 
land; often common. 

2. Bhopilem A 
Haeokel. Body hemi- 
spherical; 8 separated, 
3- winged oral lobes 
from which numerous 
club-shaped filaments 
hang: 3 species, one of 
which, R. esculent a, is 

Tig. 818— BtomoUphua meleapri* (Mayer). the edible jellyfish of 

China and Japan. 

B. verrilll (Fewkes). Diameter 35 cm.; 8 rhopalia; color yellowish: 
Long Island Sound to North Carolina and southwards. 


Fig-. 219 — Diagram of ■ longitudinal 
section of a foral animal ( Boas) . 1, ten- 
tacle ; 3, mouth ; 3, gullet; 4, mesentery ; 
0. baie of a mesentery which has been cut 
away ; 6, septum of the calcareous skele- 
ton covered b; a fold of the foot; T.theca; 
S, septum. 

Class 3. ANTHOZOA. (Actinozoa.) 

Corals, sea anemones, etc. Ccb- 
lenterates in which the polyp form 
alone is present) no medusa gener- 
ation appearing. The body (Fig. 
219) is usually cylindrical in form 
and is attached either permanently 
or temporarily at one end, which, 
in the sea anemones, is called the 
foot or pedal diac. The other and 
flattened end is the oral disc; in its 
center is the month surrounded by 
hollow tentacles, which may num- 
ber from six to several hundred. 
The month is not round, but an 
elongated slit, at one or both ends 
of which is a prominent, ciliated 

groove called the aiphonoglyph, through which the genital products may 

reach the outside (Fig. 220). The mouth does not lead directly into the 

gastro vascular space, but into a 

tube lined with ectoderm called the 

gullet which opens into the gastro- * 

vascular cavity below. This cavity 

is divided into a number of com- 
municating chambers by six or 

more wide longitudinal ridges called 

the mesenteries, which spring from 

the body wall and project towards 

the center of the cavity; in the 

upper portion of the body, certain 

of these mesenteries join the body 

wall with the wall of the gullet 

(Fig. 220), thus dividing this part 

of the gastro vascular space into 

small chambers which are continued 

above in the hollow tentacles, while 

in the lower portion of the gastro 

vascular space the edges of the mes- 
enteries are free. 

Along the free edge of each mesentery is a convoluted thickening, the 

mesenterial filament, which is of great importance inasmuch as it contains 


SWeyaae). 1, alphouoglypb ; 2, gullet; 
, primary mesenteries ;_ 4. secondary 

longitudinal n 



the gonads, and also nematocysts; at its lower end also, in many species, 
are long threads called acontia charged with nematocysts which can be 
protruded from the mouth and also, in some cases, through pores (cin- 
clides) in the body wall. The mesenteries bear the retractor muscles, each 
of which appears as a prominent ridge on one side of it. At the upper end 
of the body is usually a strong sphincter muscle which draws this end 
together and closes the mouth. The body wall consists of the two main 
cell layers and the mesoglea, which contains nuclei The mesenteries are 
composed of mesoglea and entoderm; the important retractor muscles and 
the gonads being thus of entoderms! origin, the latter migrating later 
into the mesoglea of the mesenteries where they are found. 

Very characteristic is the skeleton, which most Anthozoa possess. This 
is composed either of calcium carbonate or a horn-like substance called 
ceratine, both of which are secreted by the ectoderm and serve to elevate 
the colony in the water, bringing it into a favorable position for main- 
taining itself. 

The Anthozoa are in most cases unisexual. The ova and sperm are 
thrown into the gastrovascular space, where in many cases a portion of 
the development may be carried on. In some sea anemones, the young are 
carried awhile in pits on the side of the body. After a short free life, the 
young animal settles to the bottom, and in most cases becoming fixed, 
develops into the adult animal. Asexual reproduction by budding is very 
general and leads to the formation of the colonies which are so character- 
istic of the group. All of the Anthozoa are marine animals and are espe- 
cially numerous in the warmer parts of the world. Corals are of impor- 
tance to man because of the coral reefs, banks, and islands they help to 
form. The only species which have commercial importance are the red 
corals of the Mediterranean and Japan which are used in the manufacture 
of jewelry. The name of the class originated with Ehrenberg, who in 
1831 divided the polyps as then known into two groups, the Anthozoa or 
flower flnimAla and the Bryozoa or moss animals. The class contains 
over 2,000 living and many fossil species, which are grouped in two 

Key to the orders of Anthozoa: 

Ox Eight pinnate tentacles present 1. Alcyonaria 

o, Tentacles simple and usually numerous 2. Zoantharia 

Order 1. ALCYONARIA.* 

Colonial Anthozoa with 8 pinnate tentacles and 8 mesenteries (Fig. 
222, B). A siphonoglyph is present on but one side of the polyp, or not 
at all. The retractor muscles are all on the same side of the mesen- 

• 8ee "Alcyonaria of Porto Rico," by C. W. Hargitt and C. R. Sogers, Ball. U. 
8. Hah. Com., VoL 20, p. 267, 1900. 


teries, that which looks towards the siphonoglyph. The skeleton con- 
sists of calcium carbonate or ceratine spicules imbedded in the mesoglea, 
but formed by cells of ectodermic origin, which may be fused together in 
the center of the colony so as to form a compact axis: in a few genera 
a skeleton is lacking. The mesoglea, stiffened thus by the spicules, 
together with the outer ectoderm, is called the coenenchym. The polyps 
are seated in depressions in the coenenchym, into which they can usu- 
ally retract, and are in communication with one another by means of 
entodermal canals (Fig. 222, B). The Alcyonaria are often brightly col- 
ored and phosphorescent and are among the most conspicuous objects in 
the tropical seas. The order contains about 33 families and over 600 living 
species, grouped in 5 suborders. 

Key to the suborders of Alcyonaria here described: 

Ox Colony fixed and stationary. 

bx Polyps rise from a stolon 1. Stolonifeha 

6, Colony erect. 

Ox Central skeletal axis absent 2. Alcyonacea 

c, Central skeletal axis present 3. Gobqonacea 

Ot Colony not fixed or stationary 4. Pennatulacea 

Suborder 1. STOLONIFERA. 

Colony consists of independent polyps which rise from a mem- 
branous or ribbon-like stolon ; they are not continuously joined but may 
be united by transverse tubes or plates: 3 families. 


Polyps not joined together except by the creeping stolon from which 
they spring; spicules usually absent: about 15 genera, 

Corititlabiella Verrill. Upper portion of polyp retractile into the 
rigid lower portion; spicules present: 1 species. 

C. modesta Ver. Polyps 6 to 18 mm. high and 3 mm. in diameter; 
color of stolons and lower part of polyps yellow or brown : Casco Bay to 
Gulf of St. Lawrence, from 30 fathoms to deep water. 

Suborder 2. ALCYONACEA. 

Colony usually branching, without central axis; coenenchym with 
spicules and usually fleshy: about 10 families and over 100 species. 


Colony simple or branching and more or less massive; polyps elon- 
gate and joined by entodermal canals; coenenchym with numerous 
spicules: about 12 genera. 

ALOTOvnrM L. Colony composed of short, thick lobes and soft or 
leathery; polyps long and, with the exception of the outer end with the 


tentacles, entirely buried in the mass of the eoBnenchym which forms 
the bulk of the colony: numerous species. 

A. carnexun Agassiz. Colony yellowish or reddish in color, lobed 
or arborescent and 4 to 10 cm. high: from Long Island Sound to Gulf 
of St. Lawrence, from low water to 80 fathoms. 


Colony more or less dendritic, consisting of a sterile trunk and 
branches bearing polyps; consistency soft and leathery; polyps not 
retractile, with tentacles folded over oral disc when at rest: 10 genera. 

Spongodes Lesson. Colony massive or dendritic; spicula in periph- 
ery of polyps so numerous that neither the polyp nor their tentacles 
are retractile; polyp surrounded by giant spicules which project from 
its base beyond the tentacles: 40 species. 

8. portoricensis Hargitt. Colony about 45 mm. high, whitish in 
color, densely spinose : near Porto Rico, in 75 fathoms. 

Suborder 3. GORGONACEA. 

Sea fans, sea whips, red coral, etc. Colony usually branching exten- 
sively and with a central skeletal axis, composed of compacted spicules, 
which is either calcareous, horn-like, or composed of calcareous alternating 
with horn-like segments; a rind of ccenenchym containing spicules covers 
this axis, in which the polyps are imbedded, being joined together by 
entodermal canals: about 11 families and over 250 species. 


Colony erect, branching, with a dense, calcareous axis of fused 
spicules surrounded by canaliferous ccenenchym bearing spicules: about 
3 genera. 

CoRAlxnm Lamarck. Red coral. Polyps white in color and re- 
tractile; spicules and axis red; axis thick and longitudinally ridged by 
entodermal canals, very hard, forming the red coral of commerce : about 
a dozen species, in the Mediterranean, eastern Atlantic, and off the coast 
of Japan. 

C. nobile (Pallas) (C. rubrum Lam.). Colony up to 30 cm. high: in 
the central and western Mediterranean, being fished principally off the 
coast of Africa and Italy. 


Colony erect and branched, often in one plane; axis horn-like, occa- 
sionally horn-like and calcareous; polyps occur in rows and on two sides 
only of the stem and branches: 12 genera. 


Gobqoxia L. Colon; arborescent, often fan-shaped, the branches 
being in the same plane and often anastomosing so as to form a network; 
polyps retractile: numerous species. 

G. fUbellum L. Sea fan (Fig. 221). 
Colony a network with meshes 2 to 6 mm. 
wide, yellowish or reddish in color and up to 
60 cm. high and wide: South Atlantic and 
West Indies, in shallow water. 

0. aceroBii Pallas. Colony dendritic, 
with long, slender branches, the smaller 
branches being arranged pinnately, np to 80 
cm. high, straw-colored : West Indies, in shal- 
low water. 



Qorganta fiabeiiant Colony branched and erect, with the 

polyps scattered over entire surface; axis 
horn-like or horn-lite and calcareous; cesnenehym thick; polyps rather 
large and projecting: 10 genera. 

1. Etoioxa Lamouroux (Fig. 222). Colony arborescent; trunks 
cylindrical; polyp edges hi)"*"- 1 — «-»•*«■ 
axis horn-like; numerous bj 

PI*. 2Ti— Kmfcm. A. (Hsrgitt) entire colony: B, (Cnerter) cross MCdon showing 
polypi. 1, expADded polyp ; 2, longitndlnal section or polyp ; 3, con- 
tracted polyp; 4, central aiIb; B, entoderm*! canal, 


E. aim Edwards and Haime. Colon; up to SO cm. high and half 
as broad; diameter of trunks 8 to IS em.; cosnenchym thick, corky: 
West Indies. 

2. FUUAITBZLL* Kolliker. Colony arborescent; trunks cylindrical; 
axis born-like and calcareous; cup edges smooth; comencbym usually 
very thick. 

P. dichotomy Dana. Stem 12 to 20 mm. thick; branches smooth, 
club-shaped; color brownish: West Indies; very t 

Suborder 4. PENNATULACEA." 

Sea pens and sea feathers. Colony not fixed, but capable of inde- 
pendent movement and consisting of two parts, a stalk which is im- 
bedded in sand or mnd, and an upper part called the rachis, which bears 
the polyps and may have the form of a feather, a rod, a broad plate ; a 
central calcareous or horn-like axis usually present ; outer layer of mesoglea 
permeated with spicules forming a crust; polyps 
large and in communication with one another by 
entodermic canals and dimorphic, the autozooids 
being of ordinary structure, the smaller sipbono- 
zooids having no tentacles or gonads and reduced 
mesenteries and serving for the inflow and outflow 
of water through the entoderms! canals : 15 families 
and over 200 species. 


Sea feathers. Rachis elongate with paired lat- 
eral branches or pinnulae; siphon ozooids confined 
to lower side of rachis: about 4 genera. 

Pxraarnu Lamarck. Pinnulae long, from 20 
to 50 in number on each side, bearing the autozooids 
on their upper margin: several species. 

P. aculeate Danielsen (Fig. 223). Length 10 
em.; rachis with numerous spines among the sipho- 
noeooids; color deep red, stalk rose-colored, becom- Fig. 223 

ing whitish at the base: Gulf of St. Lawrence to P " , ""v"?hhk'"*" 
Carolina, in 100 to 500 fathoms; common; Europe. 

P. grandis (Ellis) (P. borealit Sars). Length up to 60 cm.; color 
orange; breadth 14 cm.: Newfoundland to Nantucket, in 100 to 600 

• See -Die Pennatullden." by A. Kolliker, Frankfort, 1ST0. 



Sea pens. Stalk short and thicker than the quadrangular rachis 
which is long and slender and bears the antozooids in oblique rows; 
antozooids retractile; siphonozooids confined to lower side of rachis: 
1 genus. 

Fuuiculima Lamarck. With the characters of tbe family : 2 species. 

F. armata Yen-ill. Length up to 60 cm.; auto- 

zooids deep purple; rachis yellowish below and 

brownish above: Newfoundland to Nantucket, in 

100 -to 400 fathoms. 

Family 3. RENILLIDAE. 

Rachis broad and circular or reniform, with 
the polyps confined to the upper surface; no axial 
skeleton : 1 genus. 

Fig. 224 

nmiiia rcnitormts Rehilla Lamarck. With the characters of the 

<C " m m H w e rj)" ur "' familv: 10 species. 

E. reniformis (Pallas) (Fig. 224). Upper part 
pink or violet in color, polyps white; 7 cm. long: on the Carolina coast, 
in shallow water; West Indies. 


Stony corals and sea anemones. Anthoeoa, often of large size, most 
of which secrete a stony or horn-like skeleton. The tentacles are usually 
simple (in tbe Australian sea anemone, Actinodendron, branched) and may 
number from ax to several hundred. 

The mesenteries (Fig. 220) are usually numerous, consisting of six 
primary pairs (protocnemes) which alone are present in the most primi- 
tive forma, and numerous secondary mesenteries (metacnemes) which 
are usually unilateral, that is, in pairs, both members of which are on the 
same side of the gullet, and arise in series, the younger and smaller pairs 
appearing between the older and larger ones. Tbe gullet is joined with 
the body wall by all of the protocnemes (except in Edwardsia) and usually 
by certain of the metacnemes, the two pairs of protocnemes which join 
the si phono glyphs with the body wall being called the directives. The order 
contains 1,500 species, grouped in three suborders. 

Key to the suborders of Zoantharia: 
a. Skeleton present ; animals mostly colonial. 

6, Skeleton bora-like 1. ASTrPATHABIA 

o. Skeleton calcareous. 8. Madbepobabu 

i»i No skeleton ; animate mostly solitary 2. ACTTNIABIA 


Suborder 1. ANTIPATHARIA. 

Black corals, Colonial Zoantharia having the appearance of alcyona- 
rians, with a black, horn-like central axis and a thin ccenenchym in which 
are no spicules; polyps usually with 6 tentacles and 6 mesenteries: 3 
families with about 100 species, most of which live in the deep sea. 


Colonies composed of long, slender stalks and branches; polyps 
with 6 tentacles, 6 primary mesenteries, and with or without 4 or 6 
secondary mesenteries; axis beset with spines and with a central canal: 
about 30 species. 

1. Antxpathes Pallas. Colony branching; axis with long, numer- 
ous spines: about 15 species. 

A. larix Esper. Colony up to 1 m. high and composed of a few 
long main stalks each bearing 6 longitudinal rows of parallel branches 
from 3 to 10 cm. long: West Indies; Mediterranean. 

2. CnutiFATHES Blainville. Colony not branched but consisting of 
a simple long and flexible and often spiral stalk: several species. 

C. spiralis (L.). Colony a meter or more long and spiral: West 
Indies; Mediterranean; Indian Ocean. 

Suborder 2. ACTINIARIA.* 

Sea anemones. Skeleton not present; animals usually solitary; 
often very brightly colored and of large size, occurring in all parts of 
the world, in all depths of water; the animals usually attach themselves 
temporarily to some more or less stationary object by the broad sucker- 
like foot, but can usually move about slowly; some live in the sand and 
a few are free-swimming: about 400 species, grouped in 4 divisions. 

Key to the divisions of Actiniaria: 

Ox Eight longitudinal ridges on the outer surface of the body. . . .1. Edwardsiae 
a. At least 12 ridges or none at all. 

bj But 2 rows of tentacles, an outer marginal and an inner. .2. Ckbiantheae 

ft, Tentacles not in two rows. 
Cj Animals colonial 3. Zoantheae 

o, Animals solitary 4. Hexactcniae 

Division 1. EDWABDSIAXS. 

Solitary sea anemones, small and slender, usually imbedded in the 
sand, the foot being pointed for burrowing; with 14 to 48 tentacles and 

• "Report of the Actinia," etc., by J. P. McMarrich, Proc. U. S. Nat. Mub., Vol. 
16, p. 119, 1893. "Synopsis of North American Invertebrates, The Actiniaria," by 
0. H. Parker, Am. Nat, Vol. 34, p. 747, 1900. "The Actinians of Porto Itico t ,, 
by J. B. Dnerden, Bull. U. S. Fish. Com., Vol. 20, p. 323, 1900. 



8 mesenteries (protocnemes), 2 additional pairs of rudimentary protoe- 
nemes and a few small metacnemes being also present; outer surface 
characterized by 8 longitudinal ridges and often incrusted with sand 
and other foreign substances: 4 genera and about 20 species. 

1. Edwa&dsia Quatrefages. Form slender, prismatic; tentacles 16 
or less in 2 circles of 8 each, of which the outer circle is the larger; 
2 siphonoglyphs : several species. 

E. elegans Verrill. Number of tentacles 16; length 25 mm.: north 
of Cape Cod, in shallow water. 

E. leidyi Ver. Number of tentacles 16; length 
30 mm.; diameter 1.5 mm.; parasitic in Mnemiopsis 
leidyi: Vineyard Sound and southwards; common. 

2. Ebwabdsiella Andres. Form cylindrical; 
tentacles more than 16, usually at least 24, of which 
8 are in the outer row: several species. 

E. lineata Verrill. Number of tentacles 18 to 30; 
length 25 to 35 mm.; diameter 3 mm.; color brown: 
from Vineyard Sound southwards, in 4 to 12 fathoms; 
common among worm tubes, rocks, etc. 

E. sipunculoides Stimpson (Fig. 225). Tentacles 
20 to 36; length 12 cm. extended; diameter 4 mm.; 
color brown: Cape Cod and northwards, in shallow 

Fig. 226 




Division 2. OEBIANTHEAE. 

Solitary sea anemones, long and slender, usually imbedded in sand 
or mud, with numerous tentacles in 2 rows, an outer, marginal, and an 
inner, circumoral row, and with numerous mesenteries; retractor and 
sphincter muscles weak or wanting in the adult, ectodermal muscles 
acting as retractors; but 1 siphonoglyph present; ectoderm with nu- 
merous gland and nettle cells which discharge sufficient mucus and 
nematocysts to form a long tube in which the animal lives: several 
genera with about 20 species. 

Cebxavthto Delle Chiaje. Lower end rounded and provided with 
a terminal pore: 2 species on the Atlantic and 3 on the Pacific 

0. americanus* Verrill. Marginal tentacles up to 125 or more; 
length of body up to 60 cm. extended; diameter 25 mm.; color brown: 
Cape Cod to Florida, in shallow water. 

*8ee "The Structure of Cerlanthos americanus," by J. P. McMorrich, Jour. 
Morph., VoL 4, p. 131, 1890. 


0. borealis' Ver. (Fig. 226). Tentacles very numerous; length of 
body up to 45 cm. extended; diameter 4 cm.: Long Island Sound to Bay 
of Fnndy, in 7 to 150 fathoms; very rare 

sooth of Cape Cod. 

Division 3. ZOAHTHEAE. 

Usually colonial sea anemones springing 
from an incrusting or stolon-like base; ten- 
tacles numerous, in 1 or 2 rows ; mesenteries 
with a characteristic arrangement; 1 siphono- 
glyph present; about 8 genera and over 75 
species, many of which are epizoio in habit, 
being inerusted on hermit crabs, sponges, 
hydroids, etc.; several genera. ~ 2?g 

1. ZOAMTHFB Cuvier. Polyps claviform Certanthu* bvreaOt 

or cylindrical, elongate, usually rising singly (wnaaw). 

from a network of stolons, and with no foreign bodies inerusted in their 

outer surface : numerous species. 

Z. sociatus (Ellis). Polyps about 17 mm. high, springing from 
stolons or rarely an inemsting membrane, or from one another; tentacles 
48 to 60 : West Indies. 

2. Epizoaxthub Gray. Surface of body inerusted with sand and 
other foreign bodies; colony consists of several individuals rising from 

a membrane-like base which may cover a variety 
of living or non-living objects. 

E. amoricanus Verrill (Fig. 227). Tentacles 
38 or more; height of polyp 25 mm. : attached to 
stones or to hermit crabs in 20 to 400 fathoms, 
from New Jersey to Gulf of Saint Lawrence. 

pjg 227 Division 4. HEXACTOUE. 

Solitary sea anemones, often of large size, 
with 6 pairs of mesenteries in the simplest forms, 
and approximate multiples of 6 in the higher ones, with usually 2 siphon- 
oglyphs and a large number of tentacles; the a n im als usually fasten 
themselves temporarily to rocks, etc., by the flat foot, which acts like a 
sucker, and can move slowly from place to place: about 300 species, 

" by J. S. Kln«aley, Tufts College 


Key to the families of Hexactiniae here described: 

a. Pedal disc absent ; asuallj sand dwellers 1. Haloampidai 

a, Pedal disc present 
6, Acontia absent. 

o, Body tnberculated. 2. Bunodidar 

c, Body not tuberculated 3. Pabactuab 

6, Acontia present 4. Saoabthdak 


Pedal disc absent, the lower end being rounded or pointed and often 
swollen; mesenteries few in number, 6 pairs of protocnemes with 4 
to 6 pairs of metacnemes being present; no special sphincter; tentacles 
12 to 36 : about 6 genera. 

1. Halcakfa Oosse. Body long and slender with longitudinal 
grooves and composed of 3 sections, an oral retractile portion, an inter- 

(from Parker). 

mediate portion usually coated with sand, and a pedal portion; 2 siphono- 
glyphs: several species, which live in sand and mud. 

H. fsxinacea Verrill (Fig. 22S). Tentacles 12 in 2 rows; body 
25 nun. long extended and 3 mm. in diameter; color whitish, with 
longitudinal bands of brown; disc yellow: north of Cape Cod, in 6 to 
10 fathoms. 

2. BtoiDiuit Agassiz. Twelve tentacles in a single row ; mouth with 
a proboscis (eonchula) : several species. 

B. parasiticnm Ag. (Fig. 229). Body 30 mm. long extended and 
6 mm thick : parasitic on Cyanea, fixing itself by the month on the manu- 
brium, subumbrella, or in the gastrovascnlar cavity; also in the sand: 
Cape Cod to Bay of Fnndy. 

3. Eloaotib Andres. Body slender and very contractile; tentacles 
short and blunt or capitate and in two rows : 5 species. 

E. prodncta And. (Fig. 230). Tentacles 20; body with 20 longitu- 
dinal ridges, 25 cm. long extended; diameter IS mm.; color whitish or 
salmon : South Carolina to Cape Cod, buried in the sand or on the under 
side of stones in shallow water. 


Family 2. BUNODIDAE. 

Body often of large size, with a strong entodermal sphincter and 
usually a tubereulated outer surface: about 10 genera. 

1. BmroSES Gosse. Outer surface with longitudinal rows of tuber- 
cles; tentacles rather short, retractile: 15 species. 

B. stella Verrill (Fig. 231). Body 50 mm. high; oral disc 35 mm. 
wide; tentacles 48 to 72: north of Cape Cod, in shallow water. 

2. Auxactinia Verrill. Outer surface with longitudinal rows of 
tubercles on upper half; lower half smooth: several species. 

A. capitata Ver. Body 15 cm. high and 35 mm. in diameter; ten- 
tacles 96 in 4 circles: North Carolina to Florida, in shallow water. 

3. Epiaotib Verrill. Outer surface of body with a band of egg 
pits around its middle: 1 species. 

B. prolifera Ver. (Fig. 232). Height 10 mm.; diameter 12 mm.; 

Fig. 232 Fig. 233 

Fig. 232 — Epiartit prali/wo (from Parker). 
■astcontia (From Parker). 

tentacles about 96; egg pits as many as 30 or 40: Pacific coast from 
Paget Sound to San Francisco. 

4, Teaxia Oosse. Outer surface with scattered tubercles; body 
short and thick and more or less covered with sand, bits of shell, etc.; 
tentacles short and thick : several species. 

T. crassicomifl (0. F. Miiller) (Fig. 233). Height 5 cm.; diameter 
12 em.; tentacles 160; color reddish with gray tubercles: northern seas, 
extending southward to Puget Sound and Cape Cod, in 14 to 40 fathoms; 

Family 3. PARACTIDAE. 

Anemones with a strong sphincter and a smooth outer surface : about 
10 genera. 

1. Paeaotis Milne-Edwards. Body with longitudinal grooves; ten- 
tacles slender, not very numerous, and all of equal length: several 

P. raplformii (Lesson) (Fig. 234). Body 80 mm. high extended, 
and 25 mm. in diameter; surface nearly smooth, pinkish in color; pedal 


disc small; tentacles short: buried in the sand near low water mark; from 
Cape Cod to Hatteras; Europe. 


Anemones with a sphincter and with acontia; cinclides usually present; 
tentacles usually numerous: 20 genera. 

1. Saoabtxa Gosse. Outer surface smooth; oral disc not lobed; 
cinclides present; tentacles in 3 or 4 cycles and retractile: many species. 

8. luciae Verrill. Body 8 mm. high, 6 mm. in diameter, olive green 
in color, with about 12 longitudinal orange stripes; 84 tentacles in 4 rows: 
very common on stones and shells in tide pools; Long Island Sound to 
Massachusetts Bay and farther north. 

S. leucolena Ver. Body elongate, 6 cm. long extended, 10 mm. in 
diameter, with a translucent flesh color; tentacles 96, in 4 rows: common 

Fig. 234 Fig. 235 Fig. 236 

Fig. 234— Paractis rapiformU (from Parker). Fig. 236 — Saaartia modesta (from 
Parker). Fig. 236 — Metridium dianthus (from Parker). 

under stones and in the sand in shallow water from North Carolina to 
Cape Cod. 

8. modesta Ver. (Fig. 235). Height 6 cm.; diameter 15 mm.; color 
yellowish; tentacles 60: buried to the tentacles in sand; Long Island and 
Vineyard Sounds. 

2. MsTBZDnnc Oken (Actinoloba Blainville). Outer surface smooth; 
pedal disc broad; oral disc lobed; cinclides present; tentacles very 
numerous and short : several species. 

It dianthus (Ellis) (M. marginatum Lesson) (Fig. 236). Length up 
to 10 cm., width 7 cm.; color variable, but usually brownish or yellow-? 
ish : the largest and one of the commonest sea anemones on the Atlantic 
coast; New Jersey to Labrador, from low-water mark to 90 fathoms; 
Pacific coast; Europe. 

3. Adamsia Forbes. Pedal disc adherent, the animals fixing them- 
selves to the shells of hermit crabs or to crustaceans; a band of cinclidial 
tubercles around the base of the column, the rest of which is smooth. 

A. tricolor Lesson. Height 75 mm. ; diameter 45 mm. ; tentacles 500 
or more in large individuals: on hermit crabs; North Carolina to Florida, 
in shallow water. 


Subobter 3. MADREPORARIA.' 

The stony corals. The polyps are either solitary or colonial, and 
secrete from the ectoderm a very hard, calcareous skeleton (Fig. 237). 
This usually takes the form in each case of a cup into which the polyp 
or zooid can retract itself and which consists essentially of a system of 
radial vertical plates or septa projecting into the interior of the polyp, 
but always covered with the three layers of the body wall and alternating, 
in a general way, with the mesenteries (Fig. 238). The outer edges of 
these stony septa usually join an outer wall called the theca, which is 
the outer part of the cup in which the polyp sits. In the middle of the 
cup is often a central column (columella). As the polyps grow, they 
constantly build up the theca and the septa, withdrawing from the 

terj : 8, theca. 


L, extended eon) polyp: 2, retracted 

1, septum ; 

deeper portions, which may become cut off by horizontal partitions — 
the tabulae. The colonies increase in size by growth and budding of 
the polyps, producing, in this way, the coral reefs which are such an 
important feature of tropical seas. All the reef-forming corals live in 
shallow water, 300 feet being the maximum depth in which they are 

The suborder contains over 1,000 speaies, grouped in 3 divisions. 
Most of the species are found in tropical or subtropical waters, a few, 
however, occurring in temperate and even in Arctic seas. 
Key to the divisions of Madreporaria: 

a. Coral porous ; septa not more than 12 1. PnrotATA 

a, Coral solid : septa usually numerous. 

6, Septa without cross bars 2. Apobosa 

6, Septa with cross bars 8. FuNGiClA 

• See "The Florida Reefs," by L. F. Pourtalea, Bull. Comp. Zool., To]. 6, p. 102, 
1880. "The Tortogaa and Florida Reefs," by A. Afsuls, Hem. Am. Acad., Vol. 3, 
1882. "The Btony Corals of the Porto Rtcso Waters." bj T. W. Vsngnau, Bun, 
q. S. FTsh. Con., Vol. 20, PL 2, p. 291, 1900. 


Division 1. PERFORATA. 

Corals wholly or partly porous or reticulate; zooids small with not 
more than 12 septa (Fig. 239), which are sometimes indistinct: 2 
families, which include many important 
reef-building corals. 

Colony usually branched, the coral 
being porous and containing canals con- 
necting the polyps, which are usually email 
and crowded; mesenteries in bilateral pairs; 
cnp small, deep, without columella and with 
6 or 12 septa: about S genera and over 150 
"* ^LSZFJvt? "'" Aosopoea L. (Madrepora L.). Colony 

mogWJ. branched, being either flabellate, radiate or 

thick and little branched except towards the periphery; zooids project- 
ing; terminal polyps with 6, lateral polyps with 12 tentacles; color 
usually due to symbiotic algae: many species, in most tropical seas; 1 
species in the West Indies. 

A. muricata L. Colony large (1 m. by 50 cm.), and usually spread- 
ing, with 3 common varieties; A. eervicornie Lamarck, which is loosely 
branched, A. prolifera Lam. (Fig. 240), in which 
the branches are more crowded and often fused 
together, and A. palmata Lam., made up of targe 
fan-shaped masses: West Indies and Florida. 

Family 2. PORITLDAE. 

Colony with a variety of forms, usually in- 
erusting and massive, often forming thick 
branches, but rarely dendritic; zooids small and 
close together; coral porous and made up of a 
system of trabecular and cross bars: about 12 
genera and 100 species, many of which are reef- 

Po bites' Lamarck. Cup with about 12 
short septa; columella present but often indistinct: many species, 2 
West Indian; often forming very large colonies. 

P. porites (Pallas). Colony more or less branching, there being 
3 well-marked varieties; P. clavaria Lam., consisting of very thick 


upright branches; P. furcata Lam. (Fig. 241), in which the branches 
an slender, and P. divaticata Lesueur, in which the branches are quite 

Fig. 212 

portles (VtoghBD). Pig. 242— Oeirftaa 
(ban | . A, the entire colony ; B, ■ single 
tbe acpts. 

slender (6 mm. in diameter, or less) and spreading: West Indies and 

P. aatreoides Lam. Colony not branching, but more or less globose, 
often with thick lobes: West Indies and Florida, 
Division 2. APOROSA. 
Coral solid; cup with usually numerous septa (Fig. 242, B) : about 10 

Key to the families of Aporosa here described : 

a, Mostly solitary corals 1. Tuebinoijidak 

a, Colonial corals. 

d, Zooids not contiguous 2. OcrjLraiDAJt 

b, Zocids close together or confluent 3. ASTBBIDAE 


Mostly solitary corals, with numerous septa and without a true 
theca, imbedded in the sand or attached to some object: about 50 genera 
and several hundred species, of which the greater number are fossil. 

Flabeixttk Lesson. Coral solitary, flattened more or less, tapering 
towards the base, which is attached in youth but may become detached 
later: over 50 specie*. 

F. goodci Venill. Height up to SO mm. ; greater diameter 12 cm., 
lesser 43 mm.; color in life salmon with brown stripes; a very fragile 
coral: Newfoundland to Florida, in 200 to 500 fathoms. 

Colony usually dendritic, with large zooids more or less widely sep- 
arated from one another; coral compact with 12 to 48 distinct septa and 
usually a columella: about 22 genera. 

Otnn.iNA Lamarck. Colony dendritic with spirally arranged zooids: 
many species. 


0. diffusa Lam. (Fig. 242). Colony very much branched, the 
branches forming an angle of about 30"; cups 3 mm. in diameter: North 
Carolina to Florida, often common in shallow water. 
Family 3. ASTBiBIDAE, 
Usually colonial corals with the eooids so crowded that there is 
little or no space between them, and in some cases being confluent; 
colon; compact and massive or erect; a few species are solitary: hun- 
dreds of genera and species, be- 
ing the largest family of corals. 
1. AsTXAxau Edwards and 
Haime. Colony ine rusting, the 
zooids being distinct and more 
or less isolated, with 6 septa of 
the 1st cycle, 6 smaller ones of 
the 2nd, and incomplete 3rd and 
4th cycles: 4 American species. 
A. danae Agassiz (Fig. 243). Colony small, containing from 5 to 
30 individuals, incrusted on stones, shells, etc., np to 10 cm. in diameter 
and 5 cm. high: Florida to Cape Cod, in shallow water; common. 

2. Obbioella Dana. Colony usually massive with zooids distinct 
and separated by deep concave spaces: numerous species. 

Fig. 243— Aitranpla danae (from Davenport). 

0. annularis (Lamarck) (Fig. 244). Colony globose; cups 2 mm. 
in diameter with 12 septa of the first and 12 of the second order: Florida 
and the West Indies. 

3. MxAVSaiHA Lamarck. Zooids confluent; tentacles, mesenteries, 
and septa arranged in rows; the mouths of the polyps distinct: numerous 

M. mcandrites (L.) (Fig. 245). Colony 4 to 8 cm. or more long 
and half as broad with a single large main groove and large septa; 
columella present: West Indies and Florida. 


H. sinuosa Leaueur (1'latijgyra viridti Lee.) (Fig. 246). Brain- 
coral. Colony incrusting and massive, 25 cm. in diameter or more; 
mrface made 
up of numerous 
sinuous ridges, 
which are the 
septa, and 
grooves: Wert 
Indies and 

Division 3. 
Solitary or 
colonial corals 
in which the 
septa are join- 
ed by cross 
bars or synap- 

ticula: S fami- 
ng. 246 — Meanirtna tlnuoia IVanghan). 


Coral solitary or colonial, with additional ridges (dissepiments) 
on the inner wall of the cup between the septa: about 15 genera. 


Blainville. Colony with 
distinct zooids, crowded 
and more or less polyg- 
onal, and forming 
rounded, unbranched 

S. radians (Pal- 
las). Cups about 3 mm, 
by 2 mm., rounded, with 
the fourth cycle of septa 
incomplete: West Indies. 

Flf. 247— SUerattrta Merea (Vanghan). Blderea (Ellis 

and Solander) (Fig. 
247). Cups about 5 mm. by 4.5 mm., subhexagonal, with 4 complete cycles 
of septa: West Indies, 

* See "The Cora] 8 Id eras trees/' by J. E. Daerden, Pub, Carn, lost. No. 20, 1604. 


Family 2. FUNGIIDAE. (Mushbooh Coral.) 

Coral solitary or colonial, often of large size, flat and disc-like in shape 
with numerous septa; the living disc covers the septa and from its surface 
rise very numerous tentacles; the embryo gives rise to a conical coral called 
a trophozooid, the upper part of which expands, breaks off, and becomes 
the adult coral, a process which may repeat itself a number of times: 
about 12 genera. 

Fungia Dana. Coral solitary and of large size, convex on the 
upper and concave on the lower side; without siphonoglyph : numerous 
species, 1 American. 

F. elegans Verrill. Coral round and thick, about 6 cm. in diameter: 
Gulf of California. 

Subphylum 3. CTENOPHORA.* 

Very soft and delicate jellyfishes which live mostly in the surface 
waters of the sea. The body is usually more or less spherical, pear-shaped 
or cylindrical in shape, and is both radially and bilaterally symmetrical. 
Its outer surface is without hard skeletal structures and bears eight 
longitudinal bands of cilia, which are the characteristic "combs" 
(Fig. 249) and the organs of locomotion. Each of these bands is com- 
posed of a series of transverse plates formed by the fusion of long cilia. 
The animal has an oral and an aboral end which are opposite each other. 
At the former is the mouth, an elongated slit which leads into a deep 
flattened cavity lined with ectoderm, called the stomach. It is into this 
space that the food is taken and digested. At the aboral end of the 
body is a slight cavity which is connected with the eight bands of cilia 
by four ciliated grooves, and in which are calcareous concretions and 
sensory cells. The sense organ thus formed is called the statocyst and 
is an organ of equilibration. 

Many ctenophores have a pair of long retractile tentacles which 
project from a pair of deep pockets in opposite sides of the body (Fig. 
249). These tentacles have short branches or pinnae and their ectoderm 
is provided with numerous peculiar adhesive cells which aid in cap- 
turing and killing the prey; they are very retractile, and can be wholly 
or partially withdrawn into the pockets. Other tentacles and projec- 
tions are also present in certain species. 

•See "Ctenophorae," by L. Agassis, Contributions to the Natural History of 
the United States, Vol. 3, p. 155, 1860. "Die Ctenophoren des Golfes ▼. Neapel," 
by C. Chun, Fauna u. Flora d. Golfes v. Neapel, Vol. 4, 1880. "The Ctenophores of the 
San Diego Region,*' by H. B. Torrey, Univ. of Cal. Pub., Vol. 2, p. 45, 1904. "Cteno- 
phores of the Atlantic Coast of North America," by A. G. Mayer, 1911. 


It will be seen that a longitudinal plane passed through the body 
which includes the month and stomach divides the body into two sym- 
metrical halves; a transverse plane, on the other hand, reveals a radial 
type of structure. 

The gas tro vascular space consists of a complex system of narrow 
tubes (Fig. 248) lined with entoderm which join the inner end of the 
stomach, and communicate with the outside also 
by means of either one or two pores at the aboral 
end of the body. Eight of these tubes which lie 
immediately beneath the eight longitudinal bands 
of cilia form the most important part of the sys- 
tem. The space between these gastrovascular tubes 
and the outer ectoderm is filled with the soft jelly- 
like mesenchyne which differs from the mesoglea 
of the other ccelenterates in that it arises as the 
result of the proliferation of definite cells during 
the early development of the animal; in it are 
nuclei and muscle libers. 

All ctenophores are hermaphroditic, the gonads f"*"teBopiw^£?™ 
consisting of a pair of bands, one male and the (iZuer). ""borafend 
other female, which lie side by side against the gitudlrai^carai*'; 10 !!! 
outer wall of the main longitudinal canals of the moatb^S.^to'Slcn. 4 " 
gastrovascular space, the genital products reaching 

the outer sea water through the mouth. The young animal passes 
through a complex metamorphosis before reaching the adult condition; 
but there is no alternation of generations. Certain genera may exhibit 
pedogenesis, reproducing in the larval stage, and again as adults. 

Ctenophores are common marine animals, often occurring in enor- 
mous schools. They are noted for their delicacy and beauty, the rapidly 
vibrating combs refracting the light and showing a rapid play of 
changing colors. They are also often highly phosphorescent at night. 
Their food consists of crustaceans, fishes, and other small animals, often 
including their own kind. The subphylum contains two classes and less 
than 100 species, 21 of which occur off the Atlantic coast. 

Key to the classes of Ctenophora; 

a, Either tentacles or oral lobes present 1. Tbntacdlata 

a, Tentacles and oral lobes absent 2. Nuda 


A pair of long tentacles present, in certain cases in the larval stage 
only, oral lobes being then present in the adult: 3 orders. 


Key to the orders of Tentaculata: 

a. Body more or leas globose or cylindrical. 

6, Long tentacles present 1. Ctdipfida 

b. No tentacles in adult animal ; oral lobes present 2. LobaTa 

a, Body compressed and ribbon-like 3. Cehtida 

Order 1. OiDZPPXDA. 

Bod; spherical or cylindrical or compressed in the plane transverse 
to the tentacular axis; tentacles very long, on opposite sides of the 
body, springing each from a deep pocket; several families. 
Body spherical or ovoid, with the 8 ribs of equal 
length: 4 genera. 

1. Plbtoobuohia Fleming. Body bat very little 
compressed; combs rather long but not reaching the oral 
or aboral areas: about 8 species. 

P. piletu (Fabricius) (P. rhododactyla Agassi;; P. 
bachei A. Agassiz) {Fig. 249). Body about 20 mm. long 
and 18 nun. wide, and very transparent; tentacles about 
15 cm. long and white or rose-colored, with long pinnae: 
from the south side of Long Island to Greenland; breeds 
in August and September; Europe; Pacific coast. 

P. brunnea Mayer. Body 12 mm. long, ovoid; stom- 
ach of an opaque yellowish -brown color; each tentacle 
with a knob-shaped end: coast of New Jersey; rare. 

2. Hebixnbu Lesson. Body much compressed, the 
tentacular axis being the wider; the 4 subtentacular 

combs longer than tbe 4 subventral ones: 1 American species. 

H. ovum (Fabricius). Body about 5 cm. long and ovoid in outline; 
tsntacles, combs, and sense organ ligbt pink in color: Arctic Ocean to 
New Jersey; rare south of Cape Cod. 

Order 2. LOBATA 

Body ovate, compressed in the plane transverse to that of the stom- 
aeb; month wide, with a large and prominent oral lobe on each side of 
it; at the base of each lobe is a pair of long projections called auricles; 
tentacles of the ordinary kind wanting in the adult, but numerous, deli- 
cate, filamentous tentacles may fringe the margin of the mouth and 
tbe auricles; aboral sense organs sunk in a pit; a larval cydippiform 
stage present, which has a pair of tentacles issuing from pockets and 
in certain genera may have sexual reproduction: several families. 

Fig, 249 



Fault 1. BOLlNOPSiDAE. 

Oral lobos of medium size; auricles short : 3 genera. 

BoLiHOFSiB Agassiz (Bolina Mertens). With the characteristics of 
the family; combs not prolonged onto the oral 
lobes: 6 genera. 

B. Infnndibalom (0. F. Miiller) (B. dlata 
Ag.) (Fig. 250). Bod; up to 15 cm. long, of 
a transparent bluish- white color: from Vine- 
yard Sound to Labrador, often very common 
north of Cape Cod. 

Fault 2. MNEMIIDAE. 
Lobes large, each bounded on each side 
by a deep lateral furrow which extends to the 
aboral end of the body; auricles long and 
slender: 4 genera. 

Mranoziis Agassiz. Auricles long and n g _ 250— BoHnopsU In- 

large; combs prolonged onto the lobes almost to {"'nek."'"™, onf'tobe; s', 
their oral ends: 3 species. mown, 

M. leidyi A. Agassiz (Fig. 251). Body np to 10 cm. long and very 

transparent, at night very phosphorescent: Long Island and Vineyard 

Sounds and south to the Carolinas, often in large 

swarms; often parasitized by a sea anemone, 

Ed-wardsia leidyi. 

K. garden! Ag. Length 4 cm.; lobes rather 
small and covered with warts; body translucent or 
bluish, in color: Chesapeake Bay to Florida; 

Order 3. OESTEDA. 

Body flattened in the plane of the tentacles 
and so enormously extended in the plane of the 
stomach that it has the shape of a ribbon which 
may be a meter or more long by 8 cm, high; 4 of 
the combe (the subtentacular) are very short, the 
ride ■ 2, oraV lobe'; *3i other 4 are very long; tentacles more or less nidi- 
moa mentary, tentacle sheaths deep: 2 genera. 

Onra Lesueur. With the characters of the order : 2 species. 
0. veneris Lea. Venus' girdle. Body transparent, shimmering with 
violet, blue, or green : tropical seas, occasionally brought to our shores by 
the Gulf Stream, fragments of the animal being occasionally seen on the 
New England coast. 



Class 2. NUDA. 
Tentacles absent: 1 family. 
Body conical or ovate and compressed, with a mouth and stomach so 
very wide that the body is much the shape of a compressed thimble; combs 
extend the length of the body; a network 
of canals throughout the body which 
ramify off from the gastrovascnlar canals: 
2 genera with few species; they are cos- 
mopolitan, often occurring in large 
swarms, and are noted for their voracity, 
sometimes swallowing other ctenophores 
larger than themselves. 

Bxbo'z Browne (Idyia Freminville). 
Body more or less conical or ovoid: about 
14 species. 

B. ovata Cbamisso and Eysenhardt 
Body often tapering from the mouth to 
the aboral pole and much compressed, 10 
cm. long, pink in color towards the north, 
milky white towards the south: Chesa- 
peake Bay to Florida; cosmopolitan; 

B. cucumia Fabricins (B. roseola 
FT*, 262-bwm oucmu (Majr). Agassiz) (Fig. 252). Body 10 cm. long, 
9 cm. wide and 6 cm. thick and rose color: Vineyard Sound to Labrador, 
often very plentiful towards the north. 

VERMES. (The Lower Worms.*) 

Worms of primitive structure and often of small size, usually without 
paired locomotory appendages or a distinct head, and with non-metameric 
and often permanently ciliated bodies. The animals are usually sluggish 
of movement and in very many cases either sessile or parasitic. 

The Vermes form a polymorphic group of animals, the eight subphyla 
of which do not necessarily bear a close genetic relationship to one another. 
They, however, have many structural features in common and many of 
the classes bear a definite relation to the trochophore larva which justifies 
the placing of them in & common group. This would rank immediately 
beneath the annelids and the other groups in which the trochophore 
represents an ancestral form. 

The class Vermes, as formed by Linnaeus, included all invertebrate 
animals except arthropods. Lamarck divided the invertebrates into several 
classes, of which one was Vermes, including in it both the unsegmented 
and segmented worms. This arrangement, although it has been followed 
by Clans, Hertwig, and other modern authors, is not now usually adopted, 
and the Vermes, when used as the name of a phylum, generally include 
the lower worms alone. 

The phylum contains 8 subphyla. 

Key to the subphyla of Vermes: 

Oj Animals mostly non-burrowing. 
(* Animals mostly locomotory. 
Cx Animals mostly not minute and very often parasitic. 

dx Flattened worms ; very many parasitic 1. Plathelminthes 

d, Round and thread-like worms; often parasitic. .. .2. Nemathelminthes 
Cj Animals minute and aquatic. 
dx Grown of cilia at forward end ; animals mostly in fresh water. 

3. Tbochelminthes 

d, No external cilia ; animals marine 7. Chjstognatha 

o, Animals sessile. 

d Animals colonial 4. Bbtozoa 

c, Animals not colonial. 

d* Animals with a two-valved shell 5. Bbachiopoda 

d, Animals form tubes 6. Phobonidea 

a, Marine worms which burrow in the sand and mud 8. Sipunculoidea 

' * See "Vermes," by H. Pagenstecher and M. Braun, Bronn's Klassen nnd 
Ordnimgen dee Thierreichs, Band 4, 1893. "Textbook of the Embryology of Inverte- 
brates, Part I," by B. Korschelt and K. Heider, translated by B. L. Mark and W. M. 




Flatworms. Flattened or in some cases cylindrical worms of soft 
texture which are found in the water or in moist earth, or which live as 
parasites in animals or plants. The body is without a distinct head or 
paired appendages and is not metamerically segmented. A body cavity is 
also wanting in most of them, the spaces between the internal organs being 
secondarily filled with a vesicular connective tissue, called parenchyma. 
The outer surface of the body is either & ciliated epithelium or a thick 
unciliated euticula and no hard skeletal structures are present except 
chitinous hooks and spines. The mouth is usually in the ventral surface 
in the TurbeUaria and at the front end of the body in the other groups, 
and an anus is not present, except in the Nemertea. A mouth and an 
alimentary tract are wanting in the tapeworms. The nervous system 
consists of paired cerebral ganglia forming a brain at the forward end 
and nerves extending to various parts of the body. Special sense organs, 
when present, consist of simple eyes, tentacles, or statocysts. The excretory 
system consists of slender tubes extending throughout the parenchyma, 
the final branches of which end in flame cells. It opens to the outside 
either through a single pore or through several paired pores. No special 
respiratory organs are present, and except in the Nemertea, no circulatory 
organs or blood fluid. The reproductive organs are complex, except 
among the Nemertea, hermaphroditism being general. Asexual reproduc- 
tion by budding or fission is common in certain groups. 

History.— Certain of the parasitic flatworms have been known from 
time immemorial. Linnffius included all invertebrates except arthropods 
(his Insecta) in the class Vermes, one of the orders of which was the 
Intestina, or worms proper. Cuvier (1798) first called attention to the 
fundamental distinction between the unsegmented and the segmented 
worms, to the former of which Rudolphi (1808) gave the name Entozoa, 
most of the unsegmented worms as then known being parasites. It was 
this author who, following however Zeder in his general classifications, 
laid the foundation of our present classification of parasitic worms, of 
which he formed five orders, the roundworms or Nematodes, the Acan- 
thocephala, the Trematodes, the tapeworms or C est odes, and the bladder- 
worms or Cystici. F. S. Leuckart and von Baer showed that these groups 
did not necessarily bear a genetic relationship to one another. Vogt in 
1851 first joined the four orders of flatworms to form a class which he 

Woodworth, 1895. "Flatworms and Mesozoa, Nemertlnes, Thread-Worma and 8a- 
gitta, Rotifers," etc., Cambridge Natural History, Vol. 2, 1896. "Lea Ver- 
midlens," by Delage et Heronard, Traite* de Zool. Concrete, Vol. 5, 1897. "A 
Student's Textbook of Zoology/' Vol. 1, by Adam Sedgwick, 1898. "A Treatise on 
Zoology, Part 4," edited by E. Bay Lankester, 1901. 


called Platelmia, while of the three orders of roundworms he formed the 
class Nematelmia, an arrangement which is still maintained. 

The subphylum contains 4 classes. 

Key to the classes of Plathelminthes : 

Ox No anus; no blood vessels; animals mostly hermaphroditic, with very 
complex genital organs. 
bg Animala with rare exceptions free-living; body ciliated externally. 


5, Animals parasitic ; not ciliated externally ; mouth when present at for- 
ward end (with some rare exceptions). 
Ci Intestine and mouth present; animals small and unsegmented. 

2. Trematodes 
o, Intestine and month absent; animals usually long and segmented. 

3. Cestodes 
a, Anns, anterior proboscis, and blood vessels present; animals mostly 

unisexual and free-living, usually long and bandlike 4. Neicebtea 


Soft, free-living flatworms, mostly tinder an inch in length, which are 
found either in the water creeping slowly over stones or plants or living 
in moist places on the land. The body is flat in shape and usually elon- 
gate, but in some cases nearly circular. The external surface is ciliated 
and from it is exuded the slimy secretion of numerous glands, in which 
are often contained minute rod-like bodies called rhabdites which are pro- 
duced in certain glandular cells either of the integument or of the paren- 
chyma. A few turbellarians possess functional nettle cells which, however, 
they have acquired from hydrozoans they have eaten, and a few have 
adhesive papillae or suckers. 

No body cavity is present, the spaces between the organs being filled 
with the parenchyma. The mouth (Fig. 263) is usually near the middle of 
the ventral surface but may in the different species vary in position from 
the forward to the hinder end. It opens into a muscular pharynx which 
is usually of large size and one of the most prominent organs in the body : 
it can usually be thrust out of the mouth so as to form a proboscis by 
means of which the animal takes and often digests its food. An intestine 
is not present in the Accela: in the other turbellarians it is either a tubular 
or a branched structure. An anus is not present, fecal matter being dis- 
charged through the mouth: in certain cases, however, the intestinal 

• Bee "Rep. Invert Vine. 8d.," by A. E. Verrlll, Rep. U. S. Com. Fish, for 1871 
and 1872. "Beob. ttber die SUsswasser Tnrbel. Nordam.," by W. A. Silllman, Zeit. 
f. wis*. Zool., Vol. 41, p. 48, 1885. "Turbellarla," by L». von Graff, Bronn's Kl. n. 
On)., Vol. 4, Abt. 1, Accela nnd Rhabdoccelida, 1904-08. "Turbellarla," by same. 
"Die Sttflswasserfauna Deutschlands," 1909. "Vergleichnng der Nordamerlkanlschen 
nnd Europftlschen Turbellarienfauna," by same, Proc Sev. Int. Zool. Cong., 1910. 
"Accela, RhabdocoMa, nnd Alloeocoela des Ostens der Vereinlgten Staaten," Ac, by 
Zelt f. wia*. Zool., Vol. 99, p. 321, 1911. 


branches open to the outside. The excretory system consists of a median 
canal or one to four pairs of longitudinal canals which open to the 
outside through usually paired pores and numerous small canals which 
penetrate the parenchyma in all directions and end in flame cells. The 
nervous system consists of a pair of ventral nerve cords, the anterior 
ends of which are enlarged to form a brain and which are joined by 
numerous transverse commissures. From the brain nerves go to the eyes 
and tentacles, when these organs are present, and also to the sensitive 
anterior end of the body. 

The reproductive organs are very complex, the animals being with 
rare exceptions hermaphroditic, and differ somewhat in the various groups. 
The genital opening, which is either single or double, is in the ventral 
surface back of the mouth. Most species lay their eggs in capsules 
which are attached to plants or stones. A few reproduce also asexually, 
by transverse fission. 

Habits and Distribution.— Most turbellarians are aquatic animals, 
living either in fresh or in salt water; only the Terricola are terrestrial. 
The largest aquatic form (Leptoplana gigas) may be 15 cm. in length, 
while the largest land turbellarians (Bipaliidae) may be 45 cm. long; the 
smallest forms are of microscopic size. They are with few exceptions 
carnivorous animals, living on small animals of all sorts: a few are 

History.— O. F. Miiller in 1776 first separated the turbellarians and 
nemerteans from the other fiatworms and placed them in the genus Pla- 
naria. Ehrenberg in 1831 named the group Turbellaria. In 1851 Vogt 
placed it with the other fiatworms in the class Platelmia. The present 
arrangement of the group is due principally to von Graff and Lang. 
About 1,100 species of turbellarians are known, grouped in 2 subclasses. 

Key to the subclasses of Turbellaria: 

o, Minute marine forms without intestine 1. Accela 

a, Intestine present 2. Cgelata 

Subclass 1. ACCELA.* 

Small, delicate marine turbellarians which are found free-swimming 
and also among the rocks and seaweed along the shore. They are often 
brightly colored, and in one genus at least (Convoluta) the pigment is 
due to a symbiotic alga. No intestine is present, the food, which consists 
of minute animals and plants, being introduced directly into the paren- 
chyma, The mouth is often near the front end of the body, a proboscis 
being often absent. Eyes are usually absent, but a statocyst lies over the 
brain. The reproductive system is simple in structure, in many species 

• See "Turbellaria, I. Accela," by L. von Graff, Das Tierreicb, 1905. 



no vaaa deferenlia or oviducts being present. The subclass contains 2 
families and about 40 species, of which 6 have been found in America. 
Key to the families of Acasla: 

a, One genital pore present 1. PboioBidaj 

ii, Two genital pores present 2. CoNVOLunnAX 

Family 1. PBOPOBIDAE. 

But one genital pore present; position of month various: 5 genera 
and 14 species. 

1. Childia von Graff. Mouth in ventral surface behind the middle; 
pharynx absent ; bursa semi- 
nalis absent; 2 male copu- 
latory organs, each with a 
chit.inons stilet : 1 species. 

0. spinosa v. Or. (Fig. 
253). Length 1.4 mm.; 
color tight yellow: Woods 

8. Ahapbbob von Or. 
Body elongate; bursa sem- 
inalis and pharynx absent: 
1 species. 

A. gardineri v. Gr. 
(Fig. 254). Length np to 
6 mm.; width 1 mm.; color 
red, but yellow at the two 
ends: Woods Hole, with 
Poly charm caudatus, which 
it resembles, but is mnch 
less numerous than it; 
i rapid. 

Pig. 253 Pig. 25 

Fig. 253 — Childia tplnoia (von Graff). 1, 

K at; 2, ovary; 3, mouth ; 4, penis ■ 5. KeolU 
g. 264— Anaperita gardineri (tod Graff). 1 
cyst i 2, mouth ; 3, ovary ; 4, genital pore. 


Family 2. C»NVOLT/TIDAE. 

Two genital pores present, the female pore being in front of the 
male; bursa seminalis present; mouth near the middle of the body: 5 
genera and 25 species. 

1. Afkavobtoxa CErsted. Body cylindrical or flattened beneath 
and narrowed behind; mouth near the middle; statocyst present; eyes 
absent: 2 species. 

A. diversicolor (Erst. (Fig. 255). Body very variable in shape, 
elliptical, with yellow at forward end; middle usually violet; length 
1 mm.; width .25 mm.: Newport, R. I., and Woods Hole, among algae in 
shallow water, common; Europe. 


2. Polychosbub Mark. Body broad and flat with either one or sev- 
eral caudal filaments: 1 species. 

P. candatus Mark (Fig. 256). 
Body with parallel sides and a deep 
notch in the hinder margin, from which 
1 to 3 caudal filaments arise; color red; 
length 4 mm. ; width 1.5 mm. : on stones 
along the beach from Casco Bay to 
Long Island Sound; often abundant; 


Subclass 2. C<ELATA. 

Turbellarians with intestine : 

Key to the orders of Ccelata: 
o. Small forms with a straight intcs- 

Flg. 2BB Fig. 2S8 

Flf. 25.1 — ApJmnoitoma dii rreicolor 
(yon Graff). 1, itatocyat; 2. female 
genital pore ; 3, bursa Bemlnalls; 4, 
male genital pore. Fig. 266— Poly 
oluem* cavdafut (Mara). 1. testis: 
2, mouth ; 3. overv ; 4, female genital 
pore ; S. male genital pore. 

, Usually larger forms witb branched 

6, Intestine with 3 main branches. 

2. Tbicladida 
b, Intestine with many large branches. 


Order 1. EHABDOCCEIJCDA. (Fia. 257.) 
Marine, fresh-water, and land turbellarians of small 
size in which the intestine is a straight and unbranched 
or at the most only slightly lobed tube or sac; yolk 
glands present or not; either 1 or 2 genital pores pres- 
ent: 23 families, grouped in 2 suborders with over 350 
species, of which about 75 have been found in this 
country; about half the species marine. 

Key to the suborders of Rhabdocmlida: 

a. Intestine a straight tube 1. Rhabdocotla 

o, Intestine sac shaped with irregular aides. .2. AxLCBOCfELA 

Suborder 1. RHABDOCCELA." 

Fig. : 

— Dla- 

doocelfd [Dalsicl 
Ha) (von Graff). 
1. mouth: 2, 
brain; 3, Intes- 
tine; 4. yolk 

genital pore ; 

Body cylindrical, fusiform, filiform, or lamellate in 
shape; intestine a tube or sac, usually with straight 
sides; usually 2 eyea and occasionally sense pits and 
statoeysts present; either a single median or a pair of 
excretory canals present; many forms reproduce asexually, by terminal 
budding: 16 families and 275 species, 48 American. 

• Bee "Monographle d. Turbellarlen, l. BbaMo coal Ida," by L. von Qraff, 1882, 


Key to the families of Rhabdoccela here described: 
a, Forward end not in form of a proboscis, or where a proboscis is present 
it cannot be retracted into a sheath. 
6, Ovary and yolk glands not distinct 

c. Single median excretory trunk present 1. Catrntjlidae 

c, A pair of excretory trunks present 2. Micbostohidae 

6, Ovary and yolk glands distinct from each other. 

d Pharynx sac-shaped and parallel to ventral surface 3. Dalyeixiidae 

e, Pharynx rosette-shaped and perpendicular to ventral surface. 

4. Ttpiiloplamiae 
a, Forward end in form of a proboscis which can be retracted into a sheath. 

6, One genital pore present 5. Poltctbthudae 

6, Two genital pores present 0. Gybatiicidak 


Mouth in ventral surface near forward end; no preoral branch of 
intestine; pharynx simple; excretory pore at hinder end, with a single 
median excretory trunk; testis and ovary median and single, the former 
in front of the latter; pigment eyes wanting; reproduction asexual as 
well as sexual, chains of individuals forming: 5 genera and about 25 
species, 14 American. 

1. Stehostokum* Schmidt. Body colorless; intestine often colored 
brown, reaching almost to the hinder end of the body; a pair of ciliated 
sense pits in front of brain and 1 to 2 pairs of light-refracting organs 
behind it: 16 species, 5 American, all but 
one in fresh water, 

S. leucops (Duges). Chain consisting 
of 8 or less individuals tip to 4 mm. long; 
light-refracting organs concave and 2 in 
number: eastern and central states; Eu- 
rope; common. p 

8. grand* Child (Fig. 258). Chain ** 

consisting of 4 to 6 individuals 2 to 2.6 . 

mm. long; color orange yellow: in fresh " 

•nd bmokUh water; common. , ™ Ssfn^SSSS^S 

S. Ekhotoiooiei Leidy. Forwu-d SSr'S "°" " '" ; & "* 
end of cylindrical body elongated into 

proboscis-like appendage at the base of which are the mouth and a pair 
of sense pits: 2 species. 

R. simplex Leidy. Body yellowish white, 5 mm. long: Philadelphia, 
at the bottom of clear brooks. 

* See "Studies on Regeneration, FUston, and Regulation of Stenoafoma," by 
<•. M. Child, Arcb. 1. EDtWick., Vol. 1C, p. 1ST, 1902. 


Family 2. MICE08T0MIDAE. 
Month in ventral surface near forward end; pharynx simple; a pair 
of excretory tubes present; sense pits and usually pigmented eyes pres- 
ent: 35 species, 6 American. 

1. Micbostokttm Schmidt. Preoral branch to intestine present; 
forward end of body not proboscis-like; hinder end tapering; chains of 
individuals formed: 15 species, in both fresh and salt water. 

M. linear* (0. F. Miiller). Body 1.8 mm. long; chain consisting of 

18 individuals 7 mm. long; color yellowish or pink; 2 red eyes present; 

nettle cells present which have been derived from ingested 

hydras; binder end with a tail on which are adhesive 

papillae: eastern states; Europe. 

M. davenport! von Graff (Fig. 259). Chain consisting 
of 4 individuals 1.5 mm. long; hinder end with numerous 
papillae; body colorless; intestine yellow; eyes absent: 
Long Island and Vineyard Sounds ; on ulva and f ucus. 
Large sac-shaped pharynx present; month near for- 
ward end of body; single genital pore present; ovary dis- 
tinct from yolk glands, which are either 1 or 2 in number 
and usually unb ranched ; testes paired ; pigment eyes usually 
present; penis usually with complex chitinous 
XJZZSfSZXT 1 parte: about 70 species, mostly in fresh 
(vod Oraii). water; 17 American. 

Daltxlua Fleming (Vortex Ehren- 
berg). Body rounded in front and tapering to a point 
behind; body not pigmented but often colored by toochlo- 
rtllae; 2 black eyes present, near which and the forward 
end is the mouth ; genital pore in posterior third of body : 
46 species, 13 American, all in fresh water. 

D. armlgera (Schmidt). Length 1 mm.; penis with 2 
short chitinous rods, each of which has a spinose ter minal 
branch: central and eastern states; common; Europe. 

D. dodgei von Graff (Fig. 260). Penis with chitinous fib. 2*0 
parts of unequal size and shape forming a transverse row <fo5a*t 

fastened to a basal piece; length 1 mm.: tbe commonest Tmooth'' 
species; eastern states; in fresh and brackish water. f.'&u&ni 

4, genital pore 
Family 4. TYPHLOPLANIDAE. 6 ' e * g ' 

Pharynx rosette-shaped, springing from the ventral wall of the 
intestine and perpendicular to the ventral body surface; ovary distinct 


from yolk glands; testes paired; rhabdites usually prominent: 60 species, 
all except one in fresh water, 8 American. 

1. Ttphloplana Ehrenberg. Excretory ducts open with the mouth 
into a common space, which opens to the outside; without genital 
atrium; dermal rhabdites absent; testes very small, near the pharynx; 
eyes absent: 2 species. 

T. viridata (Abildgaard). Body 1 mm. long, tapering at both ends, 
behind to a blunt point, colorless, but usually colored green by zoochlo- 
rellae; pharynx near middle of body with the genital pore behind it: 
eastern states; Europe. 

2. Cajbt&ada Schmidt. Excretory ducts open as in Typhloplana; 
with genital atrium; eyes usually absent; dermal rhabdites absent: 27 
species, in fresh water, 1 American. 

C. hofmanni Braun. Body 1.5 mm. long, cylindrical, rounded in 
front, tapering to a blunt point behind; pharynx somewhat in front of 
middle of body and just in front of genital pore: eastern states; Europe; 

3. Hematoma Ehrenberg. Excretory ducts open as in Typhlo- 
plana; rhabdites very prominent; testes dorsal or lateral to the yolk 

glands; genital pore in hinder third of body; mouth near 
the middle; 2 eyes present; zoochlorellae absent: 13 
species, 2 American. 

M. ehrenberg! (Focke) (M. wardii Wood worth) (Fig. 

261). Body flat, up to 15 mm. long and 4 mm. wide, but 

usually much less, tapering to both ends; forward end 

blunt, hinder end pointed: central states; Europe; vivip- 

\Z arous. 


Fig. 261 


Two ovaries, yolk glands, and testes present; forward 
end forms muscular retractile proboscis; rosette-shaped 
pharynx forward of the middle of body; but 1 genital 
(WoJSP^fh) pore: 16 species, 2 American. 
2 1 inteSSe Phonobhynohto von Graff. Male genital canal 

with a poisonous spine: 2 species. 
P. helgolandicus (Metschnikoff). Length 1.7 mm.: Long Island and 
Vineyard Sounds to the Arctic Ocean; Europe; common. 


Ovaries, yolk glands, and a single testis present; forward end forms 
a retractile proboscis; mouth with a rosette-shaped pharynx near 
middle of body; genital pores separate, in hinder part of body: 1 genus. 


Gthathix Ehrenberg. With the characters of the family: 2 species. 

El. harmaphrodltns Ehr. Bod; 2 mm. long and very contractile, 

transparent: in fresh and saltwater; eastern states; Europe; very common. 

Suborder 2. ALKEOCCELA. 
Fresh-water and marine tarbellarians in which the intestine is an 
irregular sac or tube often with lateral diverticula; 1 or 2 genital pores 
present; testes and ovaries consist of numerous 
follicles: 7 families with about 75 species, 30 

Intestine sac-shaped and without lateral diver- 
ticula; pharynx variable and in forward part 
of the body ; genital pore single 
and in hinder third of body; 
ovary and yolk glands distinct : 
30 species, 10 American. 

FtACHOSTOirra Schmidt 
Two or 4 eyes present; pharynx 
large, sac-shaped : 10 American 
species; marine. 

P. wilsonl von Graff {Fig. 
262). Length 1.5 mm.: com- 
mon at Woods Hole. 

n,.*» °"»» 2 - TEIOLAMDA. . 36w*7£?*5Ktf 

"■assr- <*»• "&> ifiSftsJs raw 

'vSffiP- Marin., fmh-mter, and $1™"?°^ A !*% 

IvflSfZ.. temrtrialturbelUrian. in which SS"^ukf iT'XS 
the intestine is composed of 3 
main trunks with many branches, one trunk extending forwards from the 
pharynx, and the other two backwards ; body flattened, with sensitive lobes, 
projections or tentacles and a pair of eyes at or near the forward end, 
and in certain species a ventrally situated sucker* mouth and genital pore 
in or behind the middle of the body; proboscis well developed: about 430 
species and 6 families grouped in 3 suborders. 

Key to the suborders of Tricladida: 
a. Aquatic triclada. 

o, Fresh- water triclada: planariana 1. PALinnoou 

6, Marine triclada 2. Mincou 

a. Terrestrial trlclads 3. Tkbkicola 



Suborder 1. PALUDICOLA.* 

Planarians. Triclads with a central mouth, a single genital pore 
behind it and an elongate, flattened body, which are found in fresh water 
under stones and on plants, also in wet places under leaves, in mud, etc.; 
their food consists of crustaceans, snails, aquatic insects, etc., also of 
dead animals, and they are themselves preyed upon by fish, insect larvae, 
etc.; they possess remarkable regenerative powers and certain species 
(Planaria maculata) are known to multiply by fission; the eggs are laid 
in eocoons which are attached to stones and plants : 1 family and about 
100 species, in fresh and often brackish water. 


With the characters of the suborder: about 6 genera. 
Key to the genera of Planariidae here described : 

Ox But 1 pharynx present. 

b x Anterior margin rounded or angular 1. Planaria 

ft, Anterior end truncated 2. Dendboccelum 

o, Many pharynges present 3. Phagocata 

1. Plajtaria 0. F. Muller. Body elongate, flattened, 
rounded or angular forward, usually with a pair of lateral 
angular projections (auricles), and pointed behind; 2 eyes, 
each in a colorless area; usually a pair of lateral, elon- 
gated, and colorless sense spots near the eye: many 
species, about 9 American. 

P. maculata t Leidy (Fig. 264). Body thin, slightly 
convex, elongate, tapering to the acute tail, 20 mm. long 
or less; head end trapezoidal, wider than the body, with 
an acute median and 2 lateral projections; mouth in 
hinder half; dorsal surface spotted irregularly with black; 
ventral surface whitish: North America; the commonest 
fresh-water planarian. 

Fig. 264 



(Wood worth) 

p, pharynx. 

• See "Contributions to the Morphology of the Turbellaria," etc., by W. M. 
Woodwortb, Bull. Mus. Comp. Zool., Vol. 31, p. 1, 1897. "Regeneration in Plana- 
rians," by T. H. Morgan, Arch. f. Bntwickelungsmech., Vol. 10, p. 58. "The Move- 
ments and Reactions of Fresh Water Planarians," by R. Pearl, Q. J. M. 8., Vol. 46, p. 
609, 1903. "The Reactions of Planarians to Light," by H. B. Walter, Jour. Bz. 
Zool., Vol. 5, p. 38, 1907. "Die SUsswasserfauna Dentschlands : Tricladida," by 
L. BUhrnlg, 1909. 

t Bee "The Life History and Normal Fission of Planaria maculata," by W. C. 
Curtis, Proc Bos. Soc. Nat. Hist., Vol. 30, p. 515, 1902. 



P. torva M. Schultze (Fig. 265). Body 13 mm. long or less; head 
rounded in front and not wider than the body; color brown or black: 
eastern and central states; Europe. 

P. gonocephala Duges (Fig. 266). Body 25 mm. long or less; head 

Fig. 265 Fig. 266 Fig. 267 

Fig. 266 — Planaria torva (Bfthmlg). Fig. 266 — Planaria gonoc&phala (Woodworth), 

Fig. 267— Planaria lugubris (BftbmJg). 

as in P. maculata; body with parallel edges as far back as the genital 
pore ; color brown or greenish : eastern states ; Europe. 

P. lugubris Schmidt (Fig. 267). Body 20 mm. long or less; head 
somewhat wider than body, rounded or bluntly triangular; color light 
brown to black; ductus ejaculatorius receives the secretion of numerous 

glands which appear on its inner surface : eastern 
and central states; Europe. 

P. simplis8ima Curtis. Body 8 mm. long or 
less, black in color; head end blunt, without lat- 
eral projections; pigment wanting over eyes; 
testes few, 4 to 5 on a side: eastern states. 

P. dortocephala Woodworth (Fig. 268). Body 
elongate, 15 mm. or more long, with acute angular 
front end and a pair of acute angular auricles; 
color brown: Illinois; common. 

P. morgan! Stevens and Boring. Body 10 
mm. or more long, with a rounded or truncated 
front end, colorless: eastern states. 

2. Dsvd&oooslttic (Ersted. Body elongate 
and flat with a truncated head end which bears a 
large sucker and a pointed tail end; head set off 
by a slight constriction from the body and with ft 
pair of short, rounded, lateral projections; mouth near the middle: 
several species. 

D. gram Wilhelmi (formerly called D. lacteum 0. F. Miiller) (Fig. 
269). Body 10 to 26 mm. long and 3 mm. wide or less, milk white in color 
with the dark-colored intestine showing through; ventral sucker at front 
end ; 2 eyes and frequently 1 to 6 accessory eye spots present : eastern states. 


Fig. 268 Fig. 260 

Fig. 268 

Planaria dortocephala 


Fig. 269 

Dendrocctlum graft 




3. Phaqogata Loidy. Body elongate and flat, with a rounded head 
end and a blunt tail end; many pharynges present which lie in a com- 
mon chamber and when extruded reach the exterior 
through a single orifice, bnt which open separately into 
the intestine: 1 species, 

P. gracilis* (Haldeman) (Fig. 270). Body 30 mm. 
long and 4.5 mm. wide or leas, black in color; 1 large 
pharynx present at the junction of the 3 main intestinal 
trunks and about 22 additional pharynges which are 
joined to the 2 lateral trunks: eastern states, often 
plentiful in brackish water. 

Subordeb 2. MARICOI^A.t 
Marine triclads. Intestinal branches but little rami- 
fied; mouth in hinder half of body; uterus behind genital 
pore: 5 families and about 30 species, which live on 
seaweed, stones, or shells, or are parasitic; 10 species on 

Fi«. 270 

(Wood worth). 

' pharyngea 

1, UJllIJliKM 

2, Intestine. 

Body flattened, with otocyst but no sense pits; front 
end more or less truncate, often with a pair of ten- 
tacle-like projections; 2 eyes, at some distance from front end: 2 genera. 
B Oirard (Gnnda 0. Schmidt). Body elongate, truncated 
in front with projecting, tentacle-like corners: IS species. 
P. Wheatland! Girard (Fig. 271). Body elongate, 
nun. long and 1 mm. wide, blackish in color; tentacles 
whitish : coast of Mew England, often common under stones 
and among algae in shallow water; Europe. 

P. warroni (Girard). Front end more or less trun- 
cate; body elongate, yellowish or brownish in color, 4 to 12 
mm. long, and 2 to 3 mm. wide: New England coast; not 

Body elongate and flattened and colorless; 2 eyes present; rhab- 
dites absent; 2 uteri present with independent openings to the outside; 

• Bee "ContrlbDtloDi to the Morphology of the Turbellarta," by W. M. Wood 
worth, Ball. Mob. Comp. Zoo]., Vol. SI, p. 1, 1891. 

t See "Marine rianariana of the New England Coast," by A. E. Terrlll, Trans. 
Conn. Acad., Vol. 8, 1B8S. " Tri c laden satud! en I. Tricladlda marlcola," by L. Bflumlg, 
Zelt 1 Witt. Zool., Tot. 81, p. 344, 1908. "On the N. A. Marine Triclads," by 
J. Wllbelml, Biol. Boll., Vol. IB, p. 1, 1908. "Tricladen," by Mime, Die Fauna a. 
Flora d. Golfea v. Neapel, 1909. 

t See "Byncojlldlnm pellucidnm," etc, by W. M. Wheeler, Jonr. Morpb., Vol. 8, p. 

in, 189*. 


egg capsules attached by a slender pedicle: 2 genera and 4 species, para- 
sitic or commensal on the gills and outer surface of Lmuhu polyphemtu. 
1. Bdeixottra Leidy. Anterior end tapering; posterior end wide, 
with a glandular disc for attachment : 3 species. 

B. Candida (Oirard) (Fig. 272). Body 15 mm. long, 
4 mm. wide, gray in color; egg capsule 2.5 to 4 mm. long; 
testicular sacs 60 to 100 in number: often very common. 
B. Wheeler. Body 8 mm. long; testicular 
sacs about 170 in number; egg capsule 1.25 mm. long; not 
so common as the above. 

B. wheeleri Wilhelmi. Body 6 mm. long, 1 mm. wide, 
Bdciivlra * ae greatest width being in front of the pharynx; sucker 
n?ettiii) not set on * l - rom D0 ^ T : on £*"»* <*'***; Dot common. 

2. Stnocsudii™ Wheeler. Body elongate, tapering 
towards both ends, which are blunt; posterior rami of intestine unite, 
forming a single median trunk: 1 species. 

S. peUucidura Wheeler (Fig. 273). Body 3 mm. long; testicular fol- 
licles large, about 14 on each side of the body; egg capsules 
.75 mm. long. 

Subobdeb 3. TERRICOLA.* 

Land planarians. Intestinal branches simply lobed; 

position of mouth variable; uterus small, behind the genital 

pore; body oval or elongate, and usually brightly colored, 

and with a creeping sole on the ventral surface : 5 families 

and about 400 species which occur mostly in 

tropical countries, living in damp places. 

Family 1. BIFALIIDAE. 
Body often very elongate, usually brightly colored, and 
with longitudinal or transverse stripes; head end broadened, 
forming plate with numerous marginal eyes; mouth median 
or post-median; genital pore back of mouth: 4 genera and 
about 90 species. 

Placocefhalub von Graff. Body often enormously 

V p$aoo* elongate; head plate thin, much broader than long, and 

kewewS with a semicircular margin: 15 species. 

(von Graff). p. kewensis (Mosley) (Fig. 274). Body 10 to 20 cm. 

(in some cases 45 cm.) long, narrow and with parallel sides, 

yellowish in color; with 7 longitudinal stripes; sole white: greenhouses in 

America and Europe; native country unknown, although possibly Samoa, 

T L. tod Graff, 



Body elongate, with more or less parallel sides; head not distinct, 
with 2 spherical eyes near the front end; mouth near the middle: 7 
genera and about 100 species. 

Rhtvohodexto Leidy. Head end very contractile and often ex- 
tended like a proboscis; body more or less cylindrical; eyes small: 35 

E. sylvaticus Leidy. Body somewhat fusiform, thick, convex above 
and flattened below, 10 mm. long, 3 mm. thick and 1 mm. wide; forward 
end narrowed and very extensile; color gray with two longitudinal 
stripes on the back and a transverse spot near the middle: eastern 
states, in woody places. 


Marine turbellarians. often of large size, with thin, leaf -like body; 
intestine with very numerous branches which ramify to all parts of the 
body; eyes numerous; otocysts, tentacles and stiff tactile cilia also often 
present; no yolk glands; 2 genital pores; mouth central or posterior; no 
asexual reproduction: 225 species grouped in 2 suborders. 

Key to the suborders of Polycladidm: 

Ot No suckers present 1. Acotylea 

a, A ventral sucker present 2. Cotylea 

Suborder 1. ACOTYLEA. 

Polyclads without a sucker; genital pores near hinder end of body: 
3 families. 

Key to the suborders of Polycladida : 

Ox Two dorsal tentacles present 1. Planocebidae 

a, No tentacles present 2. Leftoflahidae 


Two dorsal tentacles, usually containing ocelli; mouth central; 
eopulatory apparatus directed backwards; marginal and cerebral eyes 
present or absent : about 8 genera and 45 species. 

1. Plavooera Blainville. Body oval or elliptical and flattened; 
tentacles slender, situated at some distance from front end of body with 
a duster of eyes at the base of each; cerebral ocelli inconspicuous; 
genital pores separate but near together: about 25 species. 

P. nebulosa Girard. Body convex and rather thick, 29 mm. long and 
10 mm. wide, and usually olive green in color with a median dorsal 
stripe; mouth central: Charleston to Cape Cod, under stones. 

•See "Die Polycladien des Golfes von Neapel," etc., by A. Lang, Fauna u. 
Flora d. Golfes v. Neapel, xl Monographic 1884. 


P. inqnilina Wheeler (Fig. 275). Body oval, 6 mm. long and 4 mm. 
vide; edges remain in contact with the surface over which the animal 
is moving; color grayish: Vineyard Sound, mantle cavity of Fvlgur. 

Fig. STB — Ptanoeera inqvlUna (Wheeler). 1. tentacle ; 2. mcniuuv; o, n 
4, male genital pore; 6, female genital pore. Pig. 270 — Bti/lochiit 
elliptic** (Verrlll). 1, tentacle; 2, mouth. 

8. Styxocihus Ehrenberg. Body oval or elliptical and flat; ten- 
tacles short; pharynx with several accessory lobes; genital pores near 
hinder end of body: 10 species. 

8. elliptic™ (Qirard) (Fig. 276). Body flat and thin with undu- 
lating margins, 20 mm. long and 6 mm. wide, yellowish-brown in color, 
irregularly radially veined; tentacles small, white, each with a cluster 
of ocelli; 8 to 12 frontal and cerebral and numerous marginal ocelli pres- 
ent: New England coast, the commonest of the larger 
marine planarians, especially south of Cape Cod. 
Body broad, flat, thin, without tentacles; month cen- 
tral ; pharynx lobed ; usually 4 groups of ocelli, 2 cerebral 
and 2 dorsal; marginal ocelli sometimes present; male 
copulatory apparatus directed backwards: 4 genera and 
about GO species. 

Lep TO plana Ehrenberg. Body foliaceous with undu- 
lating edges; no marginal ocelli; genital pores rather 
Pig. 277 widely separated, the male pore being distant from the 

L !SS331f end ° f &* hod y- 25 species. 

(Verrtii). l variabilis (Girard) (Fig. 277). Body elliptical, 

18 mm. long and 8 mm. wide, yellowish-brown in color; ocelli conspicuous, 
the cerebral clusters containing about 30 each and the dorsal clusters about 
15: New England coast, often abundant. 


L. folium VerrilL Body very changeable, 25 mm. long and 15 mm. 
wide, yellowish or pink in color; ocelli very numerous, small, and incon- 
spicuous: New England coast. 

Suborder 2. COTTLEA. 

Polyclads with a sucker in the ventral surface behind the genital 
pores: 4 families with about 110 species. 


Body elongate and without tentacles; cerebral ocelli on the anterior 
margin of the body ; mouth immediately behind brain ; pharynx long and 
tubular: 1 genus. 

PBOBTHXOBTOinrac Quatrefages. With the characters of the family: 
8 species. 

P. gradle Girard. Body thin and translucent, yellowish-white in 
color, 4 mm. long and 1.25 mm. wide; ocelli in 4 groups: New England 
coast; not common. 

Class 2. TEEMATODE8* 

The flukes. Soft, flat or round worms which live as parasites on 
the skin or gills of fishes and other aquatic animals or in the internal 
organs of vertebrates and also of many invertebrates. The smallest are 
of microscopic size, the largest may be a number of centimeters in 
length. The outer surface of the adult body is an unciliated cuticula in 
which suckers and chitinous hooks or spines are present, which enable 
the animal to fix itself to its host. No body cavity is present, the 
spaces between the organs being filled with the vesicular parenchyma. 

The mouth is at the forward end of the body (except in Bucephalus). 
The intestine is, with a few exceptions, bifurcate and is without anal open- 
ing : the food consists of the blood and other juices of the host. The excre- 
tory system consists of two main portions, the excretory vesicles and the 
excretory tubules. The latter ramify throughout the parenchyma and end 
with flame cells. The former consist of a pair of lateral canals which 
receive the tubules and open to the outside through a pair of anterior pores 
in the Monogenea and a median posterior pore in the Digenea. The nerv- 
ous system consists of a pair of ganglia just back of the mouth which 
are joined with each other by a commissure and of nerves which pass to 

• See "Plathelmlnthes, I. Trematodes," by M. Brann, Bronn's Klassen, etc., 
Bd. 4, p. 306, 1802. "Die thlerlschen Paraslten des Menschen," by same, 1903. 
"Illustrated Key to the Trematode Parasites of Man/' by C. W. Stiles, Boll. No. 
17, Hyg. Lab., Treaa. Dept., 1004. "Index Catalogue," etc., "Trematoda," by same. 
Bull. No. 37, same, 1008. "Trematodes," by M. Ltlhe, Die SttBswaaserfauna DeutschL, 


the various organs. Several pairs of large longitudinal nerves pass to 
the hinder part of the body. 

With a few exceptions all trematodes are hermaphroditic, the male 
and female pores being either confluent, in which case a genital atrium 
is often present, or side by side and near together in the ventral sur- 
face. The arrangement of the genital organs is complex and varies 
somewhat in the three orders of trematodes. The egg is composite in 
structure, consisting of an ovum and several yolk cells. 

Habits and Distribution.— The young trematode leads a free life for a 
short time and then seeks its host. The most primitive trematodes are 
external parasites and the entire life may be passed on a single host. 
The higher forms, on the other hand, are internal parasites and live in 
two or more hosts, the adult host being different from the larval host, 
and the passage from one host to the other being accompanied by a 
metamorphosis. The former are called monogenetic and the latter dige- 
netic trematodes. Many of the latter are dangerous parasites to man 
and his domestic animals. 

History.— This class was established in 1808 by Rudolphi, who 
included in it the genera, Monostoma Zeder, Amphistoma Rudolphi, 
Distoma Retzius, and Polystoma Zeder. It was not until 1858 that the 
distinction between the ectoparasitic and the entoparasitic forms found 
expression in the classification, when P. J. van Beneden formed the groups 
Monogenea to include the former and the Digenea for the latter. In 1892 
Monticelli showed the need of subdividing the Digenea and established the 
following suborders : the Heterocotylea, the Aspidocotylea, and the Malaco- 
cotylea, the first of which coincides with the Monogenea. This subdivision 
was generally adopted, but is now being abandoned in favor of the simpler 
one of van Beneden. The explanation of the complex metamorphosis of 
trematodes was first given by Steenstrup in 1842. Thomas and Leuckart 
discovered almost simultaneously in 1881 the life history of the common 
liver fluke (Fasciola hepatica), and the latter author and Looss have 
played the principal part in the investigation of the entire group. 

About 2,500 species of trematodes are known, which may be 
grouped in 3 orders. 

Key to the orders of Trematodes: 

Ox Ectoparasitic trematodes (except Polystoma) ; hooks usually present in 

the suckers or sucking discs 1. Monogenic 

a, Mostly entoparasitic trematodes; no hooks in the suckers or sacking 
b x Either a large ventral sucking disc or a midventral row of suckers ; no 

oral sucker 2. Aspidocotylea 

ft, Usually either 1 or 2 median suckers; oral sucker present (except in 

Bucephalus) 3. Digenea 


Osdeb 1. MOHOGEJTCA.* 

Monogenetic trematodes (Fig. 278). Usually external parasites on 
fish and other aquatic animals. Most forms live on but a single host and 
are found most often on the gills, 
being that part of a fish's body where 
the blood is nearest the surface and 
where a parasite is also protected; / 

some, however, live in the mouth and f- 

some in the cloaca. The genus n 

Polyttoma is ento parasitic. The or- E 

gans of attachment are at the extremi- V 

ties of the body. At the hinder end 
is a large disc more or less sharply 

set off with either suckers or hooks, ^ a^n,™,,, of a ^—netic 

or both these organs. At the for- «^™ri ^Bucke*r- Vtraio- ™° vaaUr 
ward end is usually a pair of suckers fcaKBi \l2ftV ifaS 
with the mouth between them. These JfyW fej^ ^ 
may, however, be absent or their place B*g3&*&E&ggp ; "■ fcsteB 
may be taken by a single oral sucker, 

by paired glands, or by tentacle-like structures. The order contains 4 
families and about 500 species. 

Key to the families of Manogenea; 
a, Large posterior sucking disc without suckers or marginal hooks. 

6, A pair of anterior suckers or sucker-like projections with mouth between. 

1. Tristomidab 

t, A single anterior sucker, or none 2. MONOOOTTUDAK 

a. Disc-like posterior region with either paired suckers or marginal hooks. 

\ Posterior region with suckers 3. Poltstoiodax 

b, Posterior region without suckers 4. Qtropacttudai 

Mostly broad, flat worms, with a pair of anterior suckers or sucker- 
like membranes, one on either side of the mouth, and a large posterior 
sucking disc in which hooks are often located, the anterior suckers 
being without hooks; a pair of eye spots often present; intestine bifur- 
cate and often much branched; genital pores near the forward end, the 
male and female openings being in some cases separated from each 
other: on the skin or gills of marine fishes or in the mouth or cloaca; 
about 11 genera. 

* "Notes on Trematode Parasites of Fishes," by B. Linton, Proe. D. 8. Nat 
Una., Vol. 20, p. 507, 1898. "Notts on Borne Exotic Species of EctopsrsalHc 
Trematodes," by S. Goto, Jour. 8d. Coll., Imp. Univ., Vol. 12, p. 263, I860. 
"Synopsis of the Trematodes, Part t. The Heterocotrlea," by H. S. Pratt, Am. 
Nat, Vol. 84, p. ttts, 1900. "Fiab Parasites of the Woods Hole Region," bj B. 
Linton, BuIL Flab. Com., Vol. IB, p. 406, 1601. 


Key to the genera of Triatomidae here described: 
o, Sucking disc Dot set off from body and with 7 radial ridge*. . .1. Thibtom* 
o, Sucking disc aet off from bod; and without radial ridges. 
6, Bod; elongate ; Bucking disc terminal with man; minute books. 

2. NnzBCHXA 

b. Bod; elliptical ; sacking disc ventral with large hooks 3. Epibdelu 

1. Thibtoka Cu- 
vier. Body very flat, 
circular, or oval, with 
a pair of anterior suck- 
ers and a large ventral 
sacking disc in which 
are 7 radial ridges and 
small hooks; intestine 
with side branches; 
genital pores near the 
margin of the body; 
many testes present: 
r] about 10 species. 

T. coeduanm Cuv. 
(Fig. 279). Bodyabont 
15 mm. long and 16 
mm. wide and red in 
color: on the gills of 
the awordnab. 

2. Nitibohia von Baer. Bod; elongate, with sucking disc terminal 
and without radii; 2 large suckers at forward end; numerous testes: 1 
species, in salt and fresh water. 

N. sturionia (Abildgaard) (Fig. 280). Body red- 
dish, 16 mm. long, 5 mm. wide; socking disc globose: on 
gills of the sturgeon. 

S. Etibdella Blainville. Body elliptical and flat; 
sucking disc ventral without ridges, but often with 
papillae; 4 small eyes; 2 testes: several species. 

E. bnmpusl Linton (Fig. 281). Length 12 mm,; 
width 8 mm. : on skin of Dasyatit centrum; Woods Hole. 
Flat and circular or elliptical worms without paired m^>ct2t 

anterior suckers and with a single posterior sucking plate, (m'dHwIU). 
which is sometimes very small: on the skin, gills, or in the u R m f 'K I '. c yr8. 
cloaca of marine fishes; 7 genera. 

Mohocottlb Taschenberg. Sucking disc with 8 radial ridges; 
1 to 3 testes : on the skin or gills of skates. 



H. floridana Pratt {Fig. 282). Bod; 1.3 mm. long and .58 mm. wide; 
oral sucker present; intestinal branches joined at hinder end and pro- 
longed in a median ccecum : on the gills 
of Myliobatis fremtmrillei. 


Body flat and broad, with a more 
or less distinct disc or region at the 
binder end bearing suckers, usually 
paired, the number of which may vary 
from 2 to 120, and also in most cases 
books; anterior suckers either present 
or not: on gills of fishes and in the 
mouth, nose, and urinary bladder of 
amphibians and reptiles; about 21 
genera and 3 subfamilies. 

Key to the subfamilies of Poly- 

o. Anterior Backers absent ; either 2 or 8 
posterior suckers. 1. PoltstouKAB 
a, Anterior suckers present 

6, Posterior suckers 4 to 8 

0, Posterior nuckers very n 

Fig. 381— MoHuJetto 6 
References as In Fig. 278. 

Subfamily 1. POLYSTOMINAE. 

Posterior sucking disc distinctly set off and with 
2 or 6 large suckers arranged in pairs and also 2 
or more large books ; paired anterior suckers absent : 
about 5 genera. 

1. Poltstoiu Zeder. Body without anterior 
and with 3 pairs of posterior suckers; vagina paired 
with an opening on either margin of the anterior 
portion of the body: on the gills of frog tadpoles 
as larvae, and in the urinary bladder of amphibians 
and in the mouth, nose, and urinary bladder of 
turtles as adults; 6 species, 3 in America. 

P. oblongnm R. R. Wright. Diss attached at 
its anterior end; intestine with no side branches; 
body elliptical; cirrus with 16 spines, alternately 
large and small; length 2.5 mm.; width 1 mm.: in urinary bladder of 
mask, painted, and snapping turtles. 

Big . 282 

Manocotyle floridt 


as in fis- 2TB. 


P. coronatum Leidy. Body lanceolate, 8 mm. long, with 3 pain of 
minute hooks between the anterior pair of suckers, and 1 large and 2 
email pairs between the posterior pair: in the 
nose of the food terrapin. 

F. hassalli Goto (Fig. 283). Body ovate; 1.5 
mm. long and 1 mm. wide; disc hexagonal with 
3 pairs of small hooks between the anterior pair 
and 1 pair of large hooks between the posterior 
pair of suckers; intestine without side branches; 
in the urinary bladder of Kino- 
sternum pennsylvanicum. 

2. BFHTHJunrBA Wright 
and MacCallum. Body elon- 
gate with a small posterior 

T ^t^ii F (Oow ma disc containin g 2 krge suck- 
Referencei " ers: 2 species. 

as Id Fig. 878. r 

S. oslerl Wr. and MaeC. 
(Pig. 284). Body tapering at both ends, 4 mm. long 
and .6 mm. wide; disc wider than body; testes nu- 
merous: on Bkin and gills of Neeturw macuUOua, ' 

Sobtamilt 2. 0CTOC0TYLINAE. 

Posterior region with 8 (4) large suckers; paired 
anterior suckers present: about 12 genera. 

Key to the genera of Octocotylinoe here described : . 

a, Posterior disc-like reg-ion with median 

hooks. 1. DlSCOOOTYLK -^ jg. 

a. Median hooks not present. Sphurw»ra oilwi 


1. Diwooorrxi Diesing. Body 
elongate with small hooks in the poste- 
rior disc; posterior suckers slightly stalked and with 
strong chitinous support; vagina Y-shaped: several 

D.aUmonis Shaffer (Fig. 285). Body lanceolate; pos- 

iHKoffivu, terior Buckera aliebtly raised and with 1 pair of hooks; 

(BhwSer) 6 "^ long: 0D tne giU8 of the r*" 11 "^ trout. 

«. R i e D Ce Kg D 27B. 2- Dl0 «W>*=0*A Ooto. Body elongate; posterior 

suckers either stalked or not and acting as pincers; each 

sucker with a chitinous frame work in form of a Greek cross : on the 

gills of the SpaHdae and other marine fishes. 


D. affinlit (Linton). Body attenuate, spatnlate; anterior portion 
elliptical; posterior portion cylindrical; posterior suckers with long 
atalks; length 12 to 40 mm.: in the mouth of the flounder. 

Subfamily 3. IdCBOCOTTLINAE. 
Paired anterior suckers present; posterior disc-like region elongate 
and bearing numerous small suckers, which may be found only on one 
side, making the animal asymmetrical: 4 genera. 

MioaoooTYLE van Beneden and Hesse, popt=«<"- 
region bearing 10 to 120 pairs of minute sessile su 
on gills of marine fishes; many species. 

M. longicanda Goto. Sucker disc more thai 
the length of the body ; about 120 pairs of suckers 
ent; 7 mm. long; 2 mm. wide: on the gills of the 
flsh; Newport. 

M. pogonlae MacCallum 
286). Sucker disc about a th: 
the body; length 12 mm.: on Po 
cTomis, often very numerous. 


Minute forms occurring a 
gills of fresh-water and marine 
body minute, usually without su 
ers, but with 2 to 4 retractile t 
tacles at the forward end 
and a disc at the hinder end 
armed with numerous hooks: _ .. „ 

_ , Fig. 286— Uicraattvb 

about 9 genera. In the genus aoaoniae {MacCaMum). 

" ° Reference* aa in Fig. 278. 

Gyrodactylva a carious pawo- 

genesjs often occurs. A young individual will come 
to sexual maturity before it is born and while it is 
<- still in the maternal uterus, and produce young in its 
( from Bronn). a.p„ uterus. This last individual may also have young in 
Hon : p. p.. ph«r- its uterus, and 4 generations may thus be found, one 

jaa. Other refer- .... ., 

eucea aa In Fig. inside of another. 

Qyeodacttlub Nordmann. Minute, elongated 

worms with 2 short anterior projections and a posterior disc bearing 

about 16 marginal hooks and 2 large central ones; no eyes present: 

4 species. 

0. elegans Nordmann (Fig. 287). Length 1 mm.; width .2 mm.: on 

the. gills and skin, of the carp and other fresh-water fishes. 



Order 2. ASPIDOOOTTLEA. (Fra. 288.) 

Monogenetic and digenetic trematodea which attach themselves to 
their host by means either of a median row of suckers or a very large 
ventral sucking disc in which are sucking pits or de- 
pressions and on the margin of which are often sense 
organs; hooks and anterior suckers not present and 
intestine not bifurcate: in the intestine of fishes and 
reptiles and in mollnsks and crustaceans ; 1 family and 
a small number of species. 


Diagram of tnc 
(alter Beobam). 
1 mouth 
2. Intestine 
3, genital pore 

' -ittgf/ndi 



With the characters of the order: 8 genera. 
Key to the American genera of Aspidobothridae : 
a, Body cylindrical with a midventral row of suckers.. 

1. Stichooottu 
«, Large ventral sucking disc containing 3 or 4 longitu- 
dinal rows of depressions. 
6, Three rows present, 
e, Median depressions very elongate transversely, the 

lateral depressions being round 2. Cotylogabtsh 

c, All the depressions transversely elongate. 3. CottubfIB 

6, Four rows present 4. Aspidoqabtkr 

or Burning disc. 

1. Sttohocotyle Cunningham, Body cylindrical 
and elongate with a midventral row of 20 to 30 suckers extending the 
length of the body: 1 species. 

S. nephropis* Cunn. (Fig. 289). Length of adult 17 to 105 mm., 
with 20 to 27 suckers; length of the larva 3 to 7 mm., 
with 7 to 22 suckers: adult lives in the liver of Raja 
and the larva encysted in the intestinal walls of lob- 
sters and large crabs on the Atlantic coast; Europe. 

2. Oottlosastib Monticelli. Sucking disc long 
and narrow with 2 lateral rows of round depressions 
and a median row of very elongate transverse depres- 
sions; 2 testes; marginal sense organs: 2 species, in 
the intestine of marine and fresh-water fishes. 

0. oeddeutalisf Niekerson (Fig. 290). Sucking disc with 132 to 144 
depressions; length 10 mm.: in the sheepshead in Minnesota. 

Els. 289 


a larva from a 




as In Hi. 288. 

* Bee "Ueber die getchlechtsrelfe Form von Stlchocotyle nephropis Cunn.." by 
T. Odbner, ZooL Ans., ToL 21, p. BOO, 1898, 

t "Cotjlogaater occldentalla n, up. and a Berlilon of the Family Aspldo- 
bothrldae," by W. 8. Niekerson, ZooL Jabrb. Abt. (. Syi., Vol. IB. p. SOT, 1903. 
"Synopsli of the Trematodes, Fart II. The Aspldocotylea," etc., by a. 8. Pratt, 
Am. Nat., ToL 8ft, p. 8ST, 1902. 



accident alit 
a* Id Fig. 288. 

S. OoTYUira Leidy. Sucking disc broadly elliptical with 3 rows 
of transversely elongated depressions; marginal sense organs and 2 eyes 
present, : in the mantle cavity of mussels and the intes- 
tine of turtles; 2 species. 

0. Insignia* Leidy (Fig. 291). Length 1.8 mm.; num- 
ber of depressions about 29 : on the kidney 
of Anodonta; common. 

4. Abpieogabtj5» von Baer. Small 
worms in which the body consists of a cyl- 
indrical anterior portion and a very large 
elliptical ventral disc in which are 4 longi- 
tudinal rows of sucking depressions, num- 
bering 64 to 120 and with marginal sense 
organs ; 1 testis : in the intestines of fishes 
and in fresh-water pelecypods and marine 
gastropods; several species. 
A. conchicola v. Br. (Fig. 292). Body elongate; number of depres- 
sions about 64; length 3 mm.; 34 marginal sense organs: mostly in the 
liver, pericardium, and kidney of Unto and Anodonta; Europe. 

Order 3. DIGENEA.f (Fig. 293.) 
Entoparaeitic, digenetic trematodes living in two or 
more hosts, to which they attach themselves by means of 
either one or two median 
snckers. One of these is al- 
ways an oral sucker and at 
the front end of the body, ex- 
cept in Bucephalus; the second 
sucker, when present, is either 

on the ventral surface or at the hinder end 

of the body and is called the acetabulum. 

A few blood-infesting forms are without 

suckers. In the Holostomidae an additional 

organ of attachment in form of a large die 

or projection back of the acetabulum is also 

present. Hooks are never present in con- 
nection with the suckers but in some eases 

with the genital organs, and the body ■ 

often covered with small spines. The median 

UHF1|. 288. 

263— DIsit 

98— Plana! 

bam, altered). 1, oral i 
er ; 2, brain ; 3, sei 
pore; 4, Intestine; 5, 

7, acetabulum ; 8, o 

of a 

pore ; 14, uterus, 

* See "On the Habits and Structure or Cotjlaapls Snslgnls," etc, by H. L. 
Osborn, Zool. Jahrb. Abt f. Anat.. Vol. 21, p. 201. 

t See "Synopsis of the Trematodes, Fart II. The Aipldoeotylea and the 
eocotylea," etc, by H. S. Pratt, Am. Mat, Vol. 33, p. 887, 1002. 


excretory pore is at the hinder end of the body and the genital pore is 
in the ventral surface or on the margin of the bod;. Special sense 
organs are with rare exceptions absent. The life history is known of 
but very few trematodes. The young animal passes ont of the host in 
the egg, on leaving which it is usually a ciliated larva called the 
miracidium; this larva seeks an intermediate 
host, often a mollusk, in the body of which it 
passes its larval life, living actively or encysted 
in some of the compact tissues. It here 
passes through one or more metamarphie stages 
which finally result in the production of young 
individuals, called cercahae, each of which has 
usually a locomotive tail (in Bucephdhu two) 
(Fig. 294), which sometimes seek still another 
Cercarii of \\ intermediate host, and are destined to develop 
ITeaaent). V\ into the adult worms. If, now, the host harbor- 
cist - forming 11 ing these larval worms be devoured by the final 
i, intestine. ' \^ host, the young worms pass into the intestine or 
some other hollow organ of the latter and become 
mature. Tailless cercariae, which are quite numerous, do not leave the 
first intermediate host, but pass directly with it into the final host. 
Digenetic trematodes are common parasites, the adult worms being 
found in almost all vertebrate animals. The larval worms are usually 
found in snails, small fish, and other small animals. Some of them are 
dangerous parasites to man and his domestic animals. The order eon- 
tains about 2,000 species, grouped in 2 suborders, 
Key to the suborders of Digenea: 


Mouth in the middle of the ventral surface ; intestine sac-like and not 
bifurcate: 1 family. 


But one sucker present which is at the front end of the body; mouth 
in the middle of the ventral surface; intestine sac-like and not bifurcate; 
genital pore at hinder end: in intestine of fish, in both fresh and salt 
water; the larval forms in bivalve mollusks; 2 genera. 

BnoETHiurs von Baer (Gasterostomvm von Siebold). Yolk glands 
in two distinct groups of follicles; male genital pore at end of a papilla: 
numerous species. 


B. gncQMcmx (Rudolphi) (Fig. 296). Length 1.4 mm.; width .5 
mm.: in Tylotunu marintu and other marine fishes; larva (Fig. 294) in 
gonads and other organs of the oyster, often causing 

Sdbobdxb 2. PROSTOMATA. 
Month at the anterior end, in the oral sucker; in- 
testine bifurcate (with a few exceptions) : 4 divisions. 
Key to the divisions of Proatomata: 

a, But 1 sucker present 1. Moxostomata 

a. Two suckers present 

6, Acetabulum at hinder end 2. Awhistomata 

6, Acetabulum in ventral surface. |q t 296 

o, Additional organs of attachment not present Bucephalus 


o. Additional sucking disc or projection present. 



Division 1. MONOSTOMATA. 
Oral sucker alone present; arrangement of organs similar to that of 
the Distomata: in vertebrates, especially birds and sea turtles; several 


Large trematodes in which the intestinal trunks 
join at the hinder end; genital pore in anterior half 
of the body; ovary in front of testes: in the air 
passages of birds ; 6 genera. 

Ctclogolum Brandes. Intestinal trunks with- 
out lateral branches; uterus entirely between the 
trunks: 10 species. 

G. mut&bile (Zeder). Body elongate, attenuate 
forward and about 18 mm. long; testes small, the 
hinder one near the juncture of the intestinal trunks: 
in Gallinago and other birds. 

Body usually elongate, with a collar-like rim 
around the head; testes and ovary in hinder end of 
body, the testes being in same transverse plane with 
oejfiuaut mucaptut the intestinal trunks between them: in turtles. 

Rcfereo'ra PioMooxFHALUB Looss. With the characters of 

as in Fig. zoo. | no fgmjjy. seV eral species. 

P. renlcapltis (Leidy) (Fig. 296). Length 25 mm.; width 3 mm.; 
testes lobate : intestine of Sphargis coriacea. 


Division 2. AMPHIBTOMATA. 
Body often more or less conical, with the oral sucker at the front 
end and the acetabulum at the hind end of the body; intestine bifur- 
cate, the pharynx often having a pair of lateral pockets; testes 1 or 
2 in number, large, and situated in front of the small ovary; yolk 
glands usually large; genital pore in the forward 
part of body: in all classes of vertebrates, usually 
in the digestive tract; 3 families. 


With the characters of the division : 8 genera. 

1. PAKAxrmBTOif um Fishoder. Oral sucker 

rudimentary; acetabulum large, with the excretory 

pore just dorsal to it; no pharyngeal pockets: in 

the stomach and intestine of 

"& 2 *oiTmS£I!i vertebrates, principally mam- 
(fron.BM.lL). ntisi about ^ Bpecies 

P. cervi (Zeder) (P. conieum Zed.) {Fig. 
297). Body conical, 10 mm. long: in stomach of 
sheep and cattle; rare in this country. 

2. Diplodibottb Diesing. Acetabulum large, 
with the excretory pore in its center; pharyngeal 
pockets present: in rectum of amphibians; sev- , 
eral species. , 

D. temporatus* Stafford (Fig. 298). Body 
conical; about 3.6 mm. long: in rectum of frogs; 
not uncommon. 

Division 3. DISTOMATA-t 
Body flattened or cylindrical and often cov- 
ered with minute spines, with the oral sucker 
at the front end and the acetabulum in the ven- ai'in Ftg"293. 

tral surface; intestine, with a few exceptions, 
bifurcate, the 2 trunks being either short or long and branched or 
simple; usually a pair of testes (in a few species several pairs) ; a single 
ovary, which is smaller than either testis, and often a large receptaculum 

• See "The Life History of WpIodlBcnH temporatoi," etc™ by L. R. Cary, ZooL 
Jabrb. Abt f. Anat.. Vol. 28, p. B95, 1909. 

t See "An Inventory of the Genera and Subgenera of the Trematode Family 
raadoltdae," by C. W. Stiles and A. Hassall. Arch, de Para*., Vol. 1, p. 81, 1RB8. 
"Weltere Beltrlge mr Kenntnlas der Trematoden Fauna Mgypt&at," etc., by A. 
Loom, ZooL Jabrb. Abt f. Sya., Bd. 12, p. 621. "Nachtrlgllche Bemertunfen," etc^ 
by A. Looes, ZooL Ani., Bd. 23, p. 601, 1900. 


seminifl present; the uterus is a long tube, containing eggs; yolk glands 
either branched or compact: parasitic as adults in the intestine and 
other hollow organs of vertebrates; over 1,700 species, the family rela- 
tionships of which are as yet more or less obscure. 
Key to the genera of Distomata here described: 

Ox Hermaphroditic distomes. 
&t Ovary in front of testes. 
Ox Uterus does not extend back of testes. 
dx Intestinal trunks with lateral projections ; ovary and testes branched. 

1. Fasciola 
da Intestinal trunks without lateral projections. 

6x Genital pore back of acetabulum 2. Pabagonimus 

e, Genital pore not back of acetabulum. 
fx Mouth surrounded by spines. 

ffx A single row of spines 3. Echinostoma 

g t A double row of spines 4. Stbphanoohasmus 

/ t No spines around the mouth. 

ffx Excretory vesicle winds between the testes 5. Ahphimebus 

ff t Excretory vesicle does not wind thus 6. Aztgia 

c, Uterus extends back of testes. 

dx Mouth surrounded by 6 long papillae 7. Bunodeba 

d % No such papillae. 
€x Intestinal trunks reach to about the middle of the body. 

fx Yolk glands branched and in middle area of body 8. Renifeb 

/, Yolk glands compact and at end of body 13. Microphallus 

e, Intestinal trunks reach the rear end of body. 
fx Genital pore near front end of body. 
ffx Genital pore near pharynx ; in lungs of frogs and toads. 

9. Pneumonceces 

la Genital pore in front of oral sucker 10. Cephalogoniicus 

f t Genital pore near acetabulum ; yolk glands compact and lobate. 

ffx Testes 2 in number 11. Gobgodebina 

ff t Testes 9 in number 12. Goboodeba 

5a Ovary behind testes. 

Ox Hinder end of body not telescopic 14. Halifegus 

c, Hinder end telescopic 15. Hemiubub 

Oa Ovary between the testes 16. Clinostomum 

a* Unisexual diatomes 17. Schistosoma 

1. Fasciola L. Body broad and leaf-like, covered with minute 
spines and with a short conical anterior end at the base of which is the 
acetabulum; intestine, excretory vesicles, and genital glands richly 
branched; genital pore in front of acetabulum: in liver of herbivores; 
about 4 species. 

F. hepatica L. Liverfluke. Length 18 to 50 mm.; width 4 to 13 
mm.; conical anterior end distinctly set off; body thin and flat: in the 
gall passages of cattle, sheep, man, and other animals, causing 
liver rot, which is often very fatal to herds ; intermediate host a snail of 
the genus Lymnaea; cosmopolitan, but rare in America, except in southern 
Texas, in Florida, and a few other places. 


F. magna* (Baasi) (Fig. 299}. Length 20 to 100 nun.; width 11 to 
mm.; body flesh-colored and thick, with anterior end not distinctly 

Paragonim*! teettermant (from Ward). 

set off: in the gall passages of cattle; 
states; life history unknown. 

i the southwestern 

2. PAueovnnrB Brann. Genital pore 
just behind the acetabulum; body thick, 
ovoid; intestinal trunks long and un- 
brancbed; testes lobate; yolk glands very 
voluminous; uterus very short: encapauled 
in the lungs of mammals ; 1 species. 

P. weatermani (Herbert) (Fig. 300). 
Body red in color, 8 to 20 mm. long; 4 to 
8 mm , wide: in lungs of oats, dogs, and 
in eastern Asia, in man. 

3. Eohinobtoha Rudotphi. Body 
elongate and spiny; acetabulum near front 
end; mouth surrounded by a reniform 
ridge in which is a row of spines, inter- 
rupted midventrally : many species. 

E. ecMnatnm (Zeder). Number of 
spines about 37; body 18 mm. long; 
1.5 mm. wide: in intestine of docks, 
chickens, geese, and swans. 

4. STEPHAHOOHABinrs Loose. Body 
elongate and spiny; acetabulum near for- 
ward end; mouth surrounded by 2 rows of spines: several species, in 

Big. 301 

with ei tended clrrui 
Pj>., prrjiharyux ; Ft 
Other references as li 




8. caana Linton (Fig. 301). Number of spines 36, 18 in each row; 
body 6 mm. long; 1 mm. wide: in rectum of the gray snapper. 

6. Anranin* Barker. Body lanceolate; acetabulum in forward 
half with the genital pore in front of it; ovary near the center of the 
body; yolk glands divided into two regions; testes, which 
may be lobate, in a row behind it with the excretory 
vesicle winding between them: several specios, in land 

A. pseudofelineuB (Ward) (Fig. 302). Body not 
spinose; length 10 to 21 mm.; width 1 to 2.5 nun.: in the 
liver of eats. 

6. Aztsl4 Loose. Body elongate; acetabulum near 
the middle, ovary far back of it, and between the two 
is the uterus; testes back of ovary: in fish. 

A. looesi Marshall and Gilbert. Length 6 mm.; 
breadth J5 mm.; body sot spinose; yolk glands back of 
acetabulum: in mouth and stomach of wide-mouthed black 
bass, pike, and dogfish. 

7. Bvkodkxa Raillet. Body 
ovate; mouth surrounded by 6 con- 
tractile projections; acetabulum near Fl«\302 

4 center of body, with genital pore in Am ^^** 

front of it; testes in hinder part of (wart*. 

p body; uterus sac-like: in fresh-water sB R in f Fig lC 2M 

B. nodnlosa (Zeder). Length 1 to 3 mm.: in 
the intestine of the perch and other fishes; inter- 
mediate host the crayfish, being found in cysts in 
various organs. 

8. Bmrut Pratt. Body elongate and spinose; 
mtsiB Kmyw acetabulum near the middle of the body with the 
"neftreDcU genital pore between it and the oral sucker; ovary 

■slant W3. just back of acetabulum; testes lobate and just 

back of ovary : in reptiles. 
R. elUpticna Pratt (Fig. 303). Body elliptical; genital pore at left 
edge of body; 4 mm. long: in mouth of Heterodon platyrhinua, the blowing 
viper, and other snakes. 

9. PramovcHZSt Looss. Body elongate; suckers small, acetabu- 
* Bee "The Trematode Qeani Optatborchla," bj F. D. Barker, Arch. 6. Parauit., 

To). 1*. p. 813, 1011. 

t Sm "DencripHona of Fonr Dlatamea." bjr H. 8. Pratt, Mark Add. Vol., p. 25. 

t Sec "On the American Representatives of Diatomum varlegatum," bj J. 

Stafford, ZooL Jabrb. AM. f. Sja., Bd. 16, p. 895, 1002. 


lum often minute; ovary and testes beck of acetabulum ; large reeep- 
taculum eeminis present; uterus usually in longitudinal folds: in longs 
of amphibians; 8 species. 

P. similiplerus (Stafford) (Fig. 304). Length 8 mm.; width 2 mm.; 
bod; spinose; testes small; uterus very voluminous and dark-colored: 
in the lungs of frogs and toads. 

10. OETHALoaoronrB Poirier. Body broad, 
spinose; acetabulum near center of body; yolk 
glands; genital pore in front of oral sucker; 
excretory vesicle extensively branched; ovary just 
back of acetabulum and testes back of it: in 

0. vesicaudus Nickerson. Body elliptical, 2 mm. 
long: in intestine of soft-shell turtles in Minnesota. 

11. OomaODXrarA Loose. Body elongate and 
" without spines; acetabulum large and in forward 
II half of body; back of it are the yolk glands, which 

are a pair of compact bodies; the ovary is back of 
these; testes 2 in number; uterus fills the hinder 
half of the body: 4 species, in urinary bladder of 
frogs and toads. 

Q. translucida (Stafford) (Fig. 305). Body 
Pnevmonaxtf widest in the middle and tapering to 

(SfWord).* both ends; 9.5 mm. long and 12 mm. 

Fig! m" " wide: in the toad and the spring 


12. O0B6ODSSA Looss. Like Gorgoderina, but with 
9 testes in 2 rows in the hinder half of the body: 2 

G, amplicava Looss. Body widest in middle ; acetabu- 
lum very large; length 3.75 mm., and .75 mm. wide: in 
the urinary bladder of the bullfrog. , 

13. MioxorHALLua Ward. Body broad with blunt 
ends; intestinal cceca very short and not reaching acetabu- 
lum; yolk glands lobate, In binder part of body; genital 

pore at left of acetabulum: in fresh-water fish. Fig. SOS 

M. opacna (Ward) (Fig. 306). Length 1.7 mm.; ^aSfi**? 
width 1 mm.; (esophagus very long: in intestine of Amia Referencei 
calva; intermediate host Cambams propinquus. u ' 8 ' 

14. Haijpesus Looss. Body elongate; acetabulum in middle of 
body; yolk glands 2 compact lobate bodies near hinder end; ovary in 
front of them and testes in front of ovary: in amphibians. 


E. occidualis Stafford. Bod; 6 mm. long; 1.5 mm. wide; testes in 
oblique plane near acetabulum: in the month of frogs. 

16. Hemicrus Rudolphi. Small, cylindrical worms, the hinder end 
of whose bodies forms an appendix which can 
be invaginated; cnticnla transversely striped; 
yolk glands compact, behind ovary, which is just 
behind the testes: in fish. 

H. appendiculatus (Rud.). Appendix from 
a third to twice the length of the body ; acetabu- 
lum much larger than oral sucker; yolk glands 
spherical; 6 mm. long: in digestive tube of her- 
ring and other marine fish; intermediate host 
usually copepods. I ' 

16. Ouxobtomttm Leidy. Elongated worms 
with month surrounded by a circular ridge; ovary 

between the testes in middle of body; intestine ***■ M»— ^jj««««m 
without pharynx and with side projections; in ufant^i. 

mouth of birds; about 10 species. 

0. marginatum (Rudolphi) (Fig. 307). Body 6 to 10 mm. long; 
1 to 2 nun. wide; yolk glands voluminous: in Ardta and other birds; 
intermediate host, the i 

sunnsh and other fishes. 
17. Schistosoma 
Weinland. Sexes sepa- 
rate; acetabulum near 
front end; male is larger tna 
female and has a deep groo 
its ventral side in which tb 
form female lies: several sr 

5" in blood of nnflmmnln in trc 

,. countries. 

8. hamatobium (Bilb 
(Fig. 308). Body cylind 
length of male 14 mm.; leng 
female 20 mm.: in the blo&u ■<• 
man, chiefly in Africa, occasionally KeJ*io««ma 

... lurmalobium 

Fig- 307 in this country. (Loobb). 

CltnosIomuiH 1, oral sucker; 

marginatum 2, aeeti ; 

(Osbiirn). S, male Indlvld- 

Baferenoes DIVISION 4. HOLOSTOMATA. ual ; 4, female 

U In Big. 293. Individual. 

Digenetic trematodes with an oral sucker and an acetabulum, and 
in addition a large variously constructed adhesive ventral disc or pro- 


jection situated just back of the acetabulum ; body in most cases made 
up of 2 distinct regions, a wider anterior portion containing the 2 
suckers and the disc, the lateral edges of which are often rolled in 
ventrally and medially, and a posterior portion containing the genital 
organs; the genital openings being at the hinder end in a deep depres- 
sion called the bursa copulatrix ; the arrangement of the internal organs 
is similar to that of the Distomata : in the intestine of vertebrates, princi- 
pally mammals and birds; about 6 genera and 60 species. 
Key to the genera of Uolostomata here described : 

a. Lateral edges of anterior portion not rolled in medially 1. Diplohtomum 

a, Edges of anterior portion rolled in. 

6, Anterior portion trough-shaped 2. HmnsTOlfCll 

D, Edges of anterior portion fused midventrally 3. Stbjgea 

1. Diflostoxuk Nbrdmann. Body composed of 2 distinct portions; 
a large sucking disc back of the acetabulum: in the intestine of the 
Crocodilia and of birds; intermediate hosts, fish; about 15 species. 

D. grande Diesing. Oral sucker and acetabulum small; sucking 

disc at the bottom of a deep cavity, the opening of which is on a conical 

projection just back of the acetabulum; 

' length 4 mm.: in the intestine of the 

snowy owL 

2. HKMiSTOtnrjr. Diesing. Anterior 
portion of body flattened, the lateral 
edges being prolonged medially, forming 
a trough; behind the acetabulum and 
sometimes projecting over it is an elon- 
gated adhesive elevation: in the liver of 
birds and mammals; about 15 species. 

Fig. 309 Ft,. 00 * • W ™ < G ° e "> < Pi *- 30fl >" 

Fig. 309— ntmtobmmm aloism Length 6 ™m.; acetabulum smaller than 
Sttsr^wS'MaT'ta nTsB the oral Bucker ' at each side oi whioh 
&. U tM&'3nSUTC » a o™*=ent*hape<l opening of glands: 
ft l «i«te , iid b ™" i ** mpm in the 8tomflch *>>d intestine of the fox 
and dog. 
S. Sisieza Abildgaard (Boloatomum Rudolphi). Lateral edges of 
the forward portion of the body prolonged medially and joined niid- 
ventrally, making this part of the body cup-shaped; behind the acetabu- 
lum is a conical adhesive elevation in a deep cavity: in the intestine of 
birds, rarely in fish and amphibians ; about 30 species. 

S. variegata (Dnjardin) (Fig. 310). Conical elevation usually pro- 
jecting from the cup; length 6 mm.; testes branched; genital bursa at 
hinder end: in gulls, grebes, and loons. 

CE8T0DE8 189 

Class 3. CESTODES.* ( Tapeworms. ) 

Soft y flat parasitic worms in which the body is made np of two 
distinct parts, a head or scolex and a strobila. The scolex contains 
either simple or complex suckers and often hooks, the organs of attach- 
ment : the strobila is composed of a series of similar segments or proglot- 
tids, each of which contains a complete set of male and female genital 
organs. In the simplest cestodes, however, no segmentation of the body 
occurs and but one set of genital organs is present (Fig. 312). The 
cestodes are digenetic entoparasites which, with a few exceptions, live in 
two different hosts; as adults they live in the intestine of a vertebrate as 
final host, and as larvae in the muscles or some other compact tissues of 
an intermediate host. The latter is some animal which is preyed upon or 
occasionally eaten by the final host. 

The scolex is without a mouth or organs of special sense. The suckers 
are mostly 2 or 4 in number; their place is sometimes taken by variously 
formed sucker-like projections called bothria (Fig. 319). Accessory 
suckers (Fig. 318) are also sometimes present, and in a few forms the 
entire scolex is absent or rudimentary and the anterior proglottids are 
modified to form a so-called pseudoscolex, by means of which the animal 
attaches itself. Hooks are often present on the scolex to assist the para- 
site in maintaining its position. In the TcenUdae they are situated on a 
central elevation called the rostellum, and in the Bhynchobothriidae on 
four long retractile projections called proboscides. 

Behind the scolex is usually a narrow unsegmented region called the 
neck, after which come the proglottids or segments, which are derived by 
a process of terminal budding from the scolex and may number from 
three to several thousand in number, in the different species. The seg- 
ments nearest the scolex are the youngest and smallest, those at the oppo- 
site end of the strobila are the oldest and the largest In Crossobofhrium, 
however, and probably also in other cestodes, a different and much more 
complex method of growth has been observed, f new segments budding 
towards the scolex as well as away from it. The genital organs are usually 

• See "Die Paraslten des Menechen," etc., by R. Leuckart, 1879. "Cestodes,* 
by M. Braun, Bronn's Klassen, etc., Bd. 4, p. 927, 1894 to 1900. 'Tapeworms of 
Poultry," C. W. Stiles, Bull. No. 12, Bureau An. Ind., 1896. "Parasites of Fishes 
of the Woods Hole Region," by B. Linton, Boll. U. 8. Fish. Com., VoL 19, p. 406, 
1900. "Die thlerlschen Parasiten des Menschen," by M. Brann, 1903. "Parasites 
of Fishes of Beaufort," by E. Linton, Bull, of Bur. of Fish., Vol. 24, p. 821, 1905. 
"Illustrated Key to the Cestode Parasites of Man," by C. W. Stiles, Bull. 25, 
Hygienic Lab., Wash., 1906. "Tenoid Cestodes of North American Birds," by B. H. 
Ransom, Bull. U. 8. Nat Mus., 1909. "Die Sasswasserfauna Deutschl.," by M. 
LOhe, 1910. "Index Catalogue," etc "Cestoda and Cestodarla," by C. W. Stiles 
and A. Hassall, Bull. 85, Hyg. Lab., Treas. Dep., 1912. 

1 8ee "The Formation of Proglottids In Crossobothrium laclnlatum Linton," by 
W. C. Curtis, Biol. BuU., Vol. II, p. 202, 1906. 


immature in the younger segments; those following contain the mature 
organs, and in the terminal segments these have in most species degener- 
ated, except the uterus, which is swollen with eggs, each of which usually 
contains an embryo. In the typical human tapeworms these ripe seg- 
ments are detached and pass out of the body of the host to the outside, 
where they break open and the young are scattered. In the Bothrioceph- 
aloidea, however, the eggs are laid in the intestine of the host and pass out 
with the feces, the terminal segments often containing no eggs. In some 
fish tapeworms the segments are detached before they are ripe and remain 
free in the intestine. The outer surface of the body is an unciliated 
euticula, while the interior contains fe vesicular parenchyma, in which 
muscle fibers as well as the other internal organs and usually also cal- 
careous concretions lie. No digestive system is present, nutrition being 
carried on by absorption through the outer surface of the body. The 
excretory system consists typically of two pairs of longitudinal canals, 
one pair being near each lateral margin, which open to the outside in the 
terminal segment. The two canals on each side are not of the same size, 
the ventral being smaller than the dorsal and often disappearing alto- 
gether. The dorsal and the ventral pair are very often connected by It 
cross canal in each segment, and fine branches extend throughout the 
parenchyma containing flame cells. The nervous system consists of a 
number of longitudinal nerves extending the length of the body connected 
in each segment by a ring commissure; in the scolex is a pair of large 
ganglia forming the brain and usually other ganglia, joined with one 
another by a complex system of commissures. 

Cestodes, with rare exceptions, are hermaphroditic animals, each seg- 
ment containing both male and female organs; in some species each seg- 
ment contains two sets of genital organs, one on each side (Fig. 322). 
The genital pores are situated either in the margin or in the ventral sur- 
face of the segment In the lowest cestodes there are three such pores, 
through which the vas deferens, the vagina, and the uterus, respectively, 
open to the outside (Fig. 315, B). In most cestodes the vas deferens and 
vagina pass to a genital atrium which has a single external opening, and 
no special uterine pore is present (Fig. 327, B). The arrangement of the 
reproductive organs is complex and varies considerably in the different 
groups of cestodes. 

Habits and Distribution.— The typical embryo of the tapeworm is a 
minute spherical animal called the onchosphere or six-hooked embryo (Fig. 
311), which is provided with three pairs of locomotory hooks. Having 
been swallowed by its first or intermediate host, either in drinking water 
or on the food of the latter, it works its way by means of its hooks into 
the blood vessels and may be carried with the blood to various parts of 

CE8T0DE8 191 

the body of the host. It imbeds itself in a muscle or other organs and 
develops into a characteristic larva called a bladder worm. This larva 
is in some cases exactly like the scolex of the adult worm and is then 
called a plerocercus. In other cases it con- 
tains besides the scolex some or all of the 
strobila, sometimes with the genital organs, 
and is called a plerocercoid. In still others 
it is an ovoid vesicle filled with a fluid and 
containing one or more scolices and no pig. sii—a, Esg of Twnia 
proglottids and is called a eysticercus, or h^ e d'°embryo ; ^ume egg 
a minute vesicle completely filled with an wUhouttte external membrane 

invaginated scolex and called a cysticer- 

coid. This larva remains quiescent in the intermediate host, but if 
this animal be devoured by the final host the larva is transferred to the 
intestine of the latter and, at once attaching itself to the intestinal wall, 
begins to produce the strobila. In a few weeks or months the entire worm 
is usually formed. 

Cestodes are among the most pronounced animal parasites and are 
found in all countries and in all of the larger animals. Man and his 
domestic animals are especially liable to infection and may be the hosts 
of some very dangerous tapeworms. 

History.— The common tapeworms of man, including both the adult 
and the larval worm, have been known to science from the time of the 
Greeks. The name Taenia for a tapeworm occurs in Pliny, and the name 
T&nia solium has been employed since the Middle Ages, when it was given 
to all the common tapeworms. The order Cestodes was established in 1808 
by Rudolph! It included however only the adult worms, the larval worms 
being placed by Rudolphi in the separate order CysticL The relation of 
the adult to the larval worms was not then understood, notwithstanding 
the fact that Goeze and Pallas in the previous century had both clearly 
indicated it, Rudolphi and all the important helminthologists of his time 
believing that tapeworms may develop by spontaneous generation in the 
places where they are found. In fact it was not until 1851 that it was 
finally demonstrated by Kiichenmeister that the bladder worm is the larval 
stage of the adult worm. This investigator showed that if Cysticercus 
piriformis be fed to a dog Taenia serrata will very shortly appear in the 
dog's intestine. He and others afterwards repeated the experiment with 
the tapeworms of the cat and of man and of other animals. In the case 
of the human tapeworms the cysticerci were given to condemned criminals 
and the adult worms were invariably found in their intestines after 
death. Rudolf Leuckart has since been the most active in the study of the 
entire group. 


The class contains not far from 1,000 species, which are distributed 
among 2 subclasses. 

Key to the subclasses of Ceatodes : 

a, No scolex ; no segmentation ; embryo with 10 hooks 1. Cebtoimbia 

a, Body usually segmented and with a scolex ; embryo with 6 hooka. 

2. Cestodbs, i . itr. 

Subclass 1. CESTODABIA. 

Small, nn segmented worms which live in fishes as adults and in 

mollusks and annelids as larvae; no distinct scolex is present although the 

forward end has a contractile papilla or a sucker ; but 1 set of genital organs 

present; uterus a winding tube with an external opening; embryo with 10 

locomotory hooks and called a lycophora: 2 genera and about 4 species. 

1. Gtxoootylx* Diesing (Fig. 312). Body leaf-like and elliptical, 

with fluted margins; a small sucker at one end and a peculiar "rosette" 

organ at the other end with a retractile proboscis: 4 


Q. fimbriate Watson. Length up to 55 mm.; width 
10 nun.; in intestines of Chinnera; California. 

2. Axpkxlxha Wagener. Body flat and leaf-like: 
forward end with a small sucker, beside which is the 
uterine pore; at the opposite end are the openings of 
the cirrus and the vagina: 2 species. 

A. foliacea (Rudolphi). Length 20 mm.: in the 
body cavity of sturgeons. 

Subclass 2. CESTODES— Serum stricto. 
Diagram of Body, except in rare cases, segmented, with a 
< Spencer '"from scolex, which, however, may be rudimentary or rs- 
l.aui-kerTS.'maie placed by a pseudoscolex; uterus with an external 
vaginai ^"uter' opening only in the Bothriocephaloidea; vaa deferens 
nerve? Voteroa; an< * vagina open usually into a genital cloaca which 
rosette. UCt: opens to the outside by a single pore: 5 orders and 
about SO genera. 
Key to the orders of Ceatodes here described : 
a, Uterine pore present ; genital organs do not degenerate in the ripe seg- 

it, No uterine pore ; ripe segments contain the gravid uterus and little else. 
&! Proboecides not present in scolex. 
Oi Four bothria usually present; yolk glands paired; principally in fishes. 

2. TnupBTLLinu 
o, Four suckers present; yolk glands not paired; in land vertebrates. 

3. Ctclophtlliuu 
6, Four retractile proboscides present in scolex ; in fishes. 4. TETPAHORHYMCeA 

CE8T0DE8 193 


Body often long, with or without distinct segmentation; scolez with 
2 suckers, one in the dorsal and one in the ventral surface, which are 
usually weak and in certain forms are highly modified by the extension of 
their edges, and may be rudimentary or wanting, when their place may 
be taken by a single accessory sucker or la pseudoscolez ; a uterine or 
birth pore present in the ventral surface; the other two genital pores 
also usually ventral but may be dorsal or marginal; testes numerous; 
ovary either distinctly or indistinctly paired and in the hinder part of 
the segment; yolk glands paired in the lateral areas of the segment; the 
genital organs do not degenerate: about 4 families; either adult or larval 
form usually in fishes. 

Key to the families of Bothriocephaloidea here described: 

Oi Uterus an irregularly coiled tube 1. Diphyllobothriidae 

a, Uterus not a coiled tube, usually sac-like 2. Pttchobothbudab 


Scolez usually without hooks, segmentation in most cases distinct, 
but sometimes wanting; cirrus (penis) without spines; uterus a long tube 
coiled back and forth across the segment: 4 subfamilies and about 15 

Key to the subfamilies of Diphyllobothriidae here described: 

(H Two suckers present. 

& x Scolez very short ; no neck present «. 1. Liguunab 

b t Scolex elongate ; neck usually present 2. Dipiiyllobothriinab 

a, But 1 sucker 3. Cyathocephalhtajb 

Subfamily 1. LIGULINAE. 

Scolez short, triangular, with small suckers and without hooks ; genital 
pores ventral: in the intestine of water birds as adults; larva a plerocer- 
coid which may be as large as the adult and is found free 
in the body cavity of fishes : 2 genera. 

1. Ligttla Bloch. Suckers and external segmentation & 

wanting in the larva, and only the forward portion exter- 
nally segmented in the adult, these segments,, however, not 
corresponding to the internal segmentation: 1 species. 

L. intestinalis (L.) (Fig. 313). Length up to 40 cm. or — 318 
more; width 10 mm.: in perch, pike, and other fresh-water {nuSfifiau 
fish as a larva, and in gulls and other water birds as [f?om a Bra C un? 

2* 80KXSTOOEPEALTO Creplin. Suckers and external segmentation 
present and distinct in the larva as well as the adult, and internal and 
external segmentation identical: 1 species. 



8, gastcrostei (Fabrieius) (Pig. 314). Length up to 30 cm.: in 
Gasterotteua and other fish and also the frog as a larva, and in water birds 
as adult. 


Scolex without hooks and with either 2 small suckers or highly modi- 

fied suckers; segmentation distinct; 

s Lube). 

and vagina open into a 
genital cloaca, the pore of 
which is ventral and in 
front of the uterine pore: 
6 genera; in higher verte- 


Cobbold (Bothriocepkalvt 
Rudolphi; Dibothriocepha- 
Scolex flattened laterally with 2 deep slit-like suckers; strobila 

Fig. 314 — Schisiocephalvt aatlerottri. A, forward 

end (Union) ; B, flsh containing the larval 

worm (Cambridge Natural History). 

r 50 species; in carnivorous 

long; uterus a long tube coiled zigzag: 
mammals and water birds. 

D. latum (L.) (Fig. 315). 
Length up to 9 m., with several yv 
thousand segments; onchosphere V 
ciliated and free-swimming: larva a * 
plerocercoid 30 mm. long found in , 

the perch and many other fishes; 
adult worm in man, also in the cat 
and dog, and com- 
mon in certain locali- 
ties, especially where 
fish is much eaten; 
in this country rare. 

Scolex usually with a single terminal sucker; outer 
segmentation indistinct or wanting; genital pores either 
ventral or dorsal or both: 1 genus. 

OYATHOOEFHALUg Kessler. With the characters of 
the subfamily: 1 species. 

0. truncatne (Pallas) (Fig. 316). Length up to 20 
mm.; with about 6 segments: in the pyloric cceca of the 

Scolex without hooks, with 2 suckers more or less developed, each 
of which may be converted into a pocket by the partial fusion of its 

Fig. 315 — niphyltahathrivm latum 
(Leuckart). A, anterior end, allowing 
Backers ; B, mature segment, i, TO ifc 
gland ; 2, blrtb pore ; 3. sterna ; 4, 
ovary; S, excretory canal; 6, nerve; 
T, testes : 8, vaginal pore ; 8, male geni- 
tal pore (cirrus) ; 10, uterine pore. 

Fig. 318 



walk, or may be subdivided into 2 portions, of which the hinder may have 
the appearance of a separate sucker; a pseudoscolex may also take the 
place of the scolex; uterus usually an extensive sac, which may occupy 
the greater part of the segment with a ventral opening; pore for cirrus 
and vagina either marginal or dorsal: 7 genera; in fishes. 

1. Abothbtuk van Beneden. Suckers shallow; a cylindrical pseudo- 
scolez may be present in place of the scolex, the hinder margin of 
which is prolonged backwards so as to project over the strobila; seg- 
mentation of hinder part indistinct; cirrus and vaginal pores marginal, 
that of uterus medium: 3 species. 

A. rugosum (Batsch). Length 25 cm. or more; breadth 4.7 mm: 
in the intestine of the cod; often common. 

2. Bothriocephalic Rudolphi (Dibothrium Diesing). Scolex elon- 
gate with rather weak suckers; no accessory suckers; segmentation 
often indistinct; neck not present; uterine opening mid ventral; common 
genital pore for cirrus and vagina middorsal: about 4 species. 

B. latinatua (Linton). Body 15 cm. long, 4 mm. broad in the 
middle, tapering towards hinder end; segmentation distinct, the posterior 
margins of the proglottids projecting backwards, making the margin of 
the strobila serrate : in Tarpon atlanticus. 


Scolex with 4 bothria, which vary much in form, being either stalked 
or not and with or without hooks and accessory suckers; a pseudoscolex 
may replace the scolex; segmentation distinct; cirrus and vagina open on 
the margin; no uterine pore; yolk glands paired: 4 families and about 
30 genera; in selachians, and also in other fish, amphibians, and reptiles. 

Key to the families of Tetraphyllidea here described: 

<*! Hooks present at the forward end of each bothrium. . . .1. Onchobothbubab 
a. No such hooks 2. Phtllobothrudab 


Hooks of various shape present in the anterior rim of the bothria; 
bothria either sessile or with short stalks; accessory suckers usually 
present; the segments usually detach themselves before sexual maturity: 
in spiral valve of selachians; 9 genera. 

1. Oalxjobothbtux van Beneden. Bothria elongate, each being 
divided by 2 transverse septa into 3 divisions of unequal size and with 
either 1 or 3 small accessory suckers and 2 or 4 simple hooks: several 

0. vertidllatum (Rudolphi). Length up to 15 cm.; length of ter- 
minal segment about 3.5 mm., width 1.7 mm.; a 3-lobed accessory sucker 
and 4 hooks in front of each bothrium; body very slender, resembling 


a white hair; scolex the size of a small pinhead : often common in spiral 
valve of the smooth dogfish. 

2. Phowobotbsiuii Linton. Bothria rectangular and elongate, 
without Bub divisions; an accessory sucker and 2 three-pronged hooka 
at the forward end of each bothriom; neck long, with, 
minute spines: 1 species. 

F. laslnm Linton (Fig. 317). Length 4 em.; terminal 
segment about 2.2 mm. long and .84 mm. wide: in spiral 
valve of the dusky shark. 

Scoiex of Seolex without hooks: bothria usually stalked and with 

fhoreioboWi- .,..,. , ... 

Hum lasium or without septa subdividing them, and with or without a 

myzorhynchus, which is & central, stalked sucker rising 

from midst of the bothria, and other accessory suckers: about 12 genera. 

Key to the genera of Phyllobothriidae here described: 
o, Bothria without transverse septa and mysorhynchus. 

6, Bothria without accessory suckers 1. Anthobothbium 

b, Bothria, with accessory suckers. 

o, Bach bothriom with 2 suckers 2. Obyg m 

c, Each botbrium with 1 sucker. 

d, Edges of bothria not or but little convoluted .3. Cbossobothbtck 

d. Edges of bothria very much convoluted 4. PHrLLOBOTHBiuit 

u, Bothria with 2 septa and with a myxorhynehui 5. ECBXKEtBOTHRIUlI 

1: Akxhobcthbiuk van Beneden. Bothria very contractile, oval 
in shape, stalked, their edges not or but little folded; without accessory 
suckers; body elongate: several species. 

A. laciniatum Linton. Length np to 21 mm.; length of terminal 
segment, about l.S mm., width 1 mm. : in spiral valve of 
sand shark and other sharks; often numerous. 

2. Obtqjutobothbxuii Diesing. Bothria stalked, 
with a larger accessory sucker in the middle and a 
smaller one at the forward end of each, which may be orow$iothri*m 
confluent; neck long: several species. '(CurSs)!* 

0. pa-alum Linton. Length 9 mm.; breadth of ter- 
minal segment about .28 mm., length 1.03 mm.: in spiral valve of the 
tiger shark; often very numerous. 

3. Ceobbobothriuii Linton. Bothria stalked, each with an acces- 
sory sticker at the forward end, and with its rim more or less convo- 
luted ; body elongate : 1 species. 

0. laciniatum Linton (Fig. 318). Length op to 25 em.; segmenta- 
tion occurs at certain times in both directions, making the middle segments 
the youngest: in the spiral valve of the sand shark; common. 


4. Phtzxobotebtux van Beneden. Bothria sessile or nearly so, 
with very convoluted edges and with an anterior accessory sucker; neck 
very long: several species. 

P. foliatum Linton. Length up to 18 cm.; length of 
terminal segment about 1.4 mm., width .9 mm.: often 
numerous in spiral valve of the sting ray. 

5. EoHXVEiBOTH&rtnc van Beneden. Bothria stalked, 
elongate or oval, and very contractile, the face of each 

being subdivided by 1 or 2 longitudinal and several trans- Bcoie* of 


verse septa; myzorhynchus present but may be wanting in raHaUie 

. (Braun). 

old worms: several species. 

E. variabile v. Ben. (Fig. 319). Length about 10 cm.; neck long: 
in the spiral valve of the common skate; often common. 


Body usually elongate; scolex with 4 simple cup-shaped suckers, 
between which a protrusile rostellum with hooks is usually present; 
segmentation distinct; no uterine pore; common genital pore usually 
marginal; yolk gland unpaired and usually behind the paired ovary: 10 
families and about 50 genera which live principally in the higher verte- 
brates; larva a cysticercus or cysticercoid, so far as known. 

Key to the families of Cyclophyllidea here described: 

o, Uterus transverse in position and either tubular, sac-like, or reticulate. 

b x Scolex without hooks 1. Anoplocephalidae 

b t Scolex with hooks. 

Cx No hooks in the suckers 2. Diptlidiidae 

c, Suckers armed with hooks 3. Davatneidab 

a, Uterus consists of a median stem and side branches 4. Tjcnhdae 


Scolex more or less spherical, without hooks but with large suckers; 
segments short and wide; uterus transverse in position and tubular, sac- 
like, or reticular: in mammals; 8 genera. 

Key to the genera of Anoplocephalidae here described : 

Os Genital pore on but one side of the segment. 

ft. Genital pores on the same side of all the segments 1. Anoflocephala 

b t Genital pores regularly or irregularly alternate 2. Bebtia 

Os Genital pores on both sides of the segment. 

K Uterus reticulate and double 4. Moniezia 

6, Uterus tubular. 

Ox Uterus a thick tube, single or double : in rodents 3. Cittot^nia 

e, Uterus undulate : in sheep 5. Thysanosoma 

• 8ee "A Revision of the Adult Tapeworms of Hares and Rabbits," by C. W. 
Stiles, Proc. U. 8. Nat. Mus. r Vol. 19, p. 145, 1896. 



Fig. 320 — Ante- 
rior end of Anoplo- 
cephala perfoliate^ 

1. Anoplocefhala Blanchard. Segments much broader than long; 
genital pores all on the same side of the segments and never on both 
sides: abont 16 species; in horses and rodents. 

A. perfoliata (Goeze) (Fig. 320). Length up to 8 
cm.; scolex large, square, with 4 projections extending 
backwards, 2 being dorsal and 2 ventral : in the ileum, 
Cfficum, and colon of the horse, often in large numbers. 
2. Bebtza Blanchard. Segments broader than 
long; genital pores regularly or irregularly alternate, 
but never on both sides of a segment: in apes, mon- 
keys, and rodents; about 6 species. 
B. americana (Stiles). Length 33 mm.; width 6 mm.; with about 
90 segments; no calcareous concretions: in porcupines; often common. 

3. Cittot-ENIA* Riehm. Segments 
broader than long with genital pores on 
both sides ; 2 sets of genital organs and 1 or 
in some cases 2 simple, transverse, tubular 
uteri in each segment; vagina always ven- 
tral to the cirrus: in rodents; 7 species. 

0. variabilis (Stiles) (Fig. 321). 
Length up to 18 cm.; breadth 10 mm.; 
cirrus pouch tubular, of equal diameter 
throughout; testes form a band in the 
median area between the ovaries: in the 
cotton-tail rabbit and the marsh hare. 

4. MoNiEZiAf Blanchard. Segments broader than long with genital 
pores on both sides; 2 sets of genital organs and 2 complex reticulate 
uteri in each segment; vagina ventral on right side and dorsal on left 
side to cirrus; interproglottidal glands along hinder 
margin of the segment: 6 species; in ruminants. 


Fig. 321— Cittotwnia variabilis 
(Stiles). A f head; B f a seg- 
ment. 1, excretory canals; 2, 
ovary; 3, testes. 



Fig. 322 — Monietia pianissimo, (Stiles). A, a segment; B, head. 1, genital pore; 

2, ovary ; 3, yolk gland ; 4, interproglottidal gland. 

M. planissima Stiles and Hassall (Fig. 322). Body very broad and 
flat and up to 2 m. long, and 26 mm. broad; interproglottidal glands 

* See "Studies on the Genus Clttotaenia," by R. A. Lyman, Stud, from Zool. 
Lab., Unlr. of Neb., No. 48, 1902. 

t See "A Revision of the Adult Cestodes of Cattle, Sheep," etc., by C. W. Stiles 
and A. Hassall, Bull. No. 4, Bur. Animal Ind., 1803. 



Fig. 323 — Moniezia expanao (Stiles). A, two segments; 
B, end view of head; g., lnterproglottidal glands. 



'^ I 


Fig. 324 — ThpsanoBoma actinoides (Stiles). A, head, 
side view and ventral view ; B, segments. 

elongate and not in groups: in small intestine of sheep and cattle; often 

M. expansa ( Rudolph i) (Fig. 323). Body up to 4 m. long and 26 
mm. wide, and often 
quite thick; interpro- 
glottidal glands a 
straight row of round 
sacs : in sheep, cattle, 
deer, and goats; com- 


Diesing. Segments broader than long with genital pores on both sides or 

only on one side, and either 2 or 1 set of genital organs; a single uterus 

in each segment con- 
sisting of an undulat- 
ing, transverse tube 
with side pockets: 2 
species, in sheep. 

T. actinoides Dies. 
The fringed tapeworm 
(Fig. 324). Length 

up to 30 cm.; width 8 mm.; head prominent; neck very flat and broad; 

hinder margin of each segment fringed: common in the west. 


Scolez usually with hooks on a rostellum; uterus made 
up of a large number of* egg sacs, or it may be absent, in 
which case the eggs are distributed throughout the par- 
enchyma; larva a cysticercoid : in birds, mammals, and 
reptiles; 10 genera. 

1. Dotxjdxtoc Leuckart. Rostellum retractile and 
with hooks; genital pores and organs double in each seg- 
ment; uterus reticular: 1 species. 

D. caninum (L.) (D. cucumerinum Rudolphi) (Fig. 
325). Length up to 25 cm.; breadth 3 mm.; ripe segments 
about 7 mm. long and 3 mm. wide and often reddish in 
eolor : in cats and dogs, and occasionally in young children ; 
cysticercoid in the dog's flea; common. 

2. Hykeholepis* Weinland. Small filiform worms with broad seg- 
ments with the genital pores all on the left and never on both sides; 

• See "An Account of the Tapeworms of the Genns Hymenolepis Parasitic in 
Man," by B. H. Ransom, Bull. No. 18, Hyg. Lab., 1904. 

Fig. 325 

(from Ward). 


rostellum retractile and with or without hooks; 3 testes in each seg- 
ment; with a sac-like uterus filling the ripe segment: about 30 species; in 
mammals and birds. 

H. nana (von Siebold). The dwarf tapeworm (Fig. 326). Length 
15 mm. or more; breadth .7 mm.; scolex with a single row of about 28 

hooks: in the small intestine of man and the rat and 
mouse; the cysticercoid lives in the intestinal villi of the 
same host; the parasite often causes diarrhea and nervous 

H. carioca (Magalhos). Length up to 8 cm.; width 
.7 mm.; rostellum without hooks; edge of strobila serrate: 
in chickens; common. 

H. dimnuta (Rudolphi). Length up to 6 cm.; width 
4 mm.; rostellum rudimentary, without hooks: in cats and 


Scolez with hooks on la retractile rostellum and 
Mvwfimotepi* numerous small hooks in the suckers; genital pore usually 

(Leuckart) on on * v one B ^ e °* * se £ ment: 3 genera; in mammals and 

Davaihea Blanchard and Railliet. Small worms; eggs in capsules 
in the middle area of the ripe segment: about 15 species. 

D. salmon! Stiles. Length 88 mm. ; breadth 3 mm. ; number of seg- 
ments about 450 ; genital pores generally alternate : in Lepus aylvaticus and 
L. melanotis. 

Family 4. TJENHDAE. 

Scolex usually with a rostellum with hooks; uterus, in the ripe seg- 
ment, composed of a median tube and lateral branches; usually long 
worms with segments longer than wide; genital pores alternating irregu- 
larly and never on both sides of a segment : several genera. 

1. Txnia L. With the characters of the family : numerous species, 
which are usually found in predacious mammals and man, the cysticer- 
cus being found in ruminants and other plant feeders. 

T. saginata Goeze. The beef tapeworm (Fig. 327). Length 10 m. 
or more, with over a thousand segments, usual length 4 to 8 m.; ter- 
minal segments about 20 mm. long and 7 mm. broad, containing a uterus 
which has from 20 to 30 branches on each side; scolex 2 mm. thick, 
without rostellum or hooks: in the human intestine; the cysticercus 
(C> bovis) is about 9 mm. long and 5 mm. thick and lives in the muscles of 
cattle, and a person may infect himself with the worm by eating rare 
beef; the commonest human tapeworm in this country. 

T. solium L. The pork tapeworm (Fig. 328). Length about 3 m., 
with about 900 segments ; terminal segment about 12 mm. long and 

Fig- 327 — TaMa taginata (Lenckart). A. head with the anterior seementa ; B, a 
■ecmeDt about a third of the distance bark from the bead ; C, terminal segment ; 
D, a piece of beef containing three cratlcercl ; P, common genital pore. Other refer- 
ence! aa In Fig. a 1 5. 

6 mm. wide, containing a uterus which has from 7 to 10 branches on 
each side; soolex about 1 mm. thick with a rostellum bearing a double 
row of abont 28 books: in the human intestine; the cysti- 
eercus (C. cellulosae) is from 6 to 20 mm. long and about 
half as wide and thick and lives normally in the muscles of 
the pig, but also lives readily in man, being found in the 
eye, brain, heart, and other organs and causing often in- 
sanity or death; rare in this country. 

T. marginata Batsch. The large dog tapeworm. 
Length up to 3 m.; terminal segments 10 mm. long and 
5 mm. wide, containing a uterus with from 4 to 8 branches 
on each side; rostellum with 2 rows of about 38 hooks: in 
the dog; eystieercus (C. tettmcolUs) in the viscera of pigs 
and ruminants; not common in this country. 

T. serrata Qoeze. The serrate dog tapeworm. Length 

itpUilm.; terminal segments 10 mm. long and 5 mm. wide, 

containing a uterus with 8 to 12 branches on each side ; edge 

of strobila serrated; rostellum with 2 rows of about 40 

hooks: in the dog; eystieercus {O. pisiformi*) about the fJStStm 

sire of a small pea, in the peritoneum of rabbits and hares; '^"neS"'* 

common. B - terminal 


T. crassicollis Rudolpbi. The cat tapeworm. Length 
up to 60 cm.; terminal segments 10 mm. long and 6 mm. wide, containing 
a uterus with about 10 branches on each side; rostellum with 2 rows of 


abont 50 hooka: in the oat; cystieercuB (C. fatdolaris) in the liver of the 

mouse and rat, where it forms a conspicuous tumor, and is peculiar in that 

it consists of a scolez and a number of segments, the 

latter, however, degenerating on arriving in the cat's 

intestine and the acolex developing a new strobila; very 

FiM- 320— lf«!lf(- 

ccpe multlcepi 

ripe segment. 

2. IfULTlOEFS Goeze. Like Ttenia but with a large 
cysticercus from the inner wall of which many scolices 
project into the interior: abont 6 species. 

M. multicops (Leske) [Ttenia ccenurus von Sie- 
bold). The gid tapeworm* (Fig. 329). Length np to 
60 cm. ; terminal segments 5 mm. long and 2 mm. broad, 
containing a uterus with about 22 branches on each side; 
rostellum with 2 rows of about 30 books: in the dog; 
cysticercus (Canurus cerebrate), which is 25 mm. in 
diameter or larger and spherical and 
contains hundreds of scolices, lives in 
the brain or spinal cord of sheep and 
occasionally cattle, causing gid or stag- 
gers; northwestern states; Europe; often killing great 
number of sheep. 

3. EoHmoooootra Rudolphi. Like Ttenia, but with 
a large cysticercus from the inner wall of which capsules 
of scolices project into the interior: several species. 

E. granulosus (Batsch) (Ttenia echinococcus von 
Siebold). The echinococcus tapeworm (Fig. 330). 
Length up to 5 mm., with but 3 or 4 segments ; rostellum 
prominent, with 2 rows of about 40 hooks: in the dog; 
cysticercus (Echinococcus polymorphic) lives in the 
liver or other organs of sheep, pigs, cattle, or other 
animals, and also in man, when it is called a hydatid 
cyst, and as it may grow to be half a foot in diameter 
and to weigh several pounds and contains thousands of 
scolices, it may cause death; often common in Europe 
but apparently rare in this country; infection obtained directly from the 
hair or tongue of dogs. 


Scolex very long, composed of 2 portions, a head which has 2 or 4 
bothria and 4 retractile and spinose proboscides, and a long head stalk; 


segmentation distinct; genital pores marginal; genital organs with the 
same arrangement as in the Tetraphyllidea : in the intestine of selachians; 
larvae encysted in teleosts; 2 families. 

With the characters of the orders: numerous genera, 
concerning the value and position of many of which much 
uncertainty prevails. 

1. Bkybohobothrxus Rndolphi. Two bothria, one 
dorsal and one ventral, which tend to converge at their 
forward, ends: many species. 

E. bnlbifer Linton (Fig. 331). Bothria oval; neck 
long and slender; length of body up to 40 mm., with 12 or 
less segments: in spiral valve of Mustelus amis; cysts in 
mackerel, biuensh, and other teleosts; common. 

2. Tettuhhybokobothhiuh Diesing. Four bothria 
present; head stalk cylindrical; many species. 

T. robnstmn (Linton). Bothria elongate; length of 

body 24 mm.: segments usually broader than long: in Rhvnchobotn- 
„.,_,, - . , rtw buibtter 

stomach and intestine of skate; common. (Linton). 

Class 4. NEMERTEA.* 
Nemerteans. Soft, very contractile, and often brightly colored fiat- 
worms, most of which are non-parasitic 
and live in the sea. The body is usually 
elongate and more or less tape-like or fili- 
form, varying in length from 5 mm. to 
30 m. in the different species; it is unseg- 
mented, but often has an simulated ap- 
pearance due to the regularly repeated 
subdivisions of certain of the internal 
organs. The mouth is in the ventral sur- 
face near the front end and the anus is at 
the hinder end of the body. Dorsal to the mouth (Fig. 332) is an opening 
into a very deep tubular pocket, extending far back into the body, a portion 

* See "Marine Nemerteans of New England and Adjacent Waters," by A. B. 
Terrlll, Trans. Conn. Acad., Vol. 8, p. 882, 1893. "Die NemerUnen," F'aana a. Flora 
d. Golfes t. Nespel. by O. Burger, 189E. ■Nemertlnt," Kl. n. Ordn., VoL 4, Bopp., 
1897. "On the Connective Tissues and Bod; Cavities of tbe Nemerteam, with Notes 
on Classification," by T. H. Montgomery, Jr., Zool Jehrb. Anat, VoL 10, p. 1. "Notes 
of the Times ot Breeding ot Some Common New England Nemerteans," by W. R. Coe, 
Science N. S., Vol. 9, p. 16T, 1899. "Nemertlol," by O. Burger, Das Tlerrelch, 1904. 
"Synopsis ot the Nemerteans, Part I," by W. R. Coe, Am. Nat, Vol. 89, p. 420. 
"Nemerteans of tbe West and Northwest Coast of North America," by W. B. Cat, 
Baa Una. Comp. Zool, VoL 47, 1905. 

Fig. 382 — Diagram of nemertean 
worn. _ lateral aspect (BUrger). 
1, proboscis pore: % Tentrs.1 gan- 
glion ; 3, month ; A, dorsal gangli- 
on ; B, dorsal nerve ; H, Intestine ; 
7, proboscis ; 8, proboscis sbeath. 



of which can be everted and thrust forward in the form of a proboscis 
(Fig. 333) ; in most hoplonemerteans this opening coincides with the 
mouth. The proboscis is often nearly as long as the body itself and can 
be thrust out far in advance. It is primarily a tactile organ and in the 
hoplonemerteans is armed with calcareous stylets of characteristic form, 
indicating that it has also an offensive function. Dorsal to the proboscis 
in most species are the openings of the so-called cephalic glands. In 
Malacobdeila a large sucker is present at the hinder end, and Nectonemertet 
possesses a pair of lateral swimming 
organs. Many heteronemerteans have 
a caudal cirrus at the posterior end. 
The outer surface of the body is a 
glandular, ciliated epithelium and is 
often brightly colored. 

No body cavity is present, the 
spaces between the organs being filled 
with a gelatinous parenchyma. The 
proboscis, however, is surrounded by a 
muscular sheath containing a corpuscu- 
lated fluid (Pig. 333,4). The digestive 
canal extends the whole length of the 
body, and is usually differentiated into 
oesophagus, stomach, intestine, and rec- 
tum. The intestine is often provided 
with regularly recurring paired diver- 
ticula and in the hoplouemerteans has 
a long intestinal cteeum, extending for- 
ward to near the front end of the body. 
Two or three longitudinal blood vessels 
with connecting branches and contain- 
ing a corpus aula ted fluid differing 
somewhat from that in the proboscis 
sheath extend the length of the body and are connected with large blood 
spaces. A pair of profusely branched longitudinal excretory canals lie 
alongside the lateral blood vessels in the anterior portion of the animal, 
which usually open to the outside through one or more pores on each side 
of the body. Minute branches of these canals extend into the parenchyma 
and end in flame cells. The central nervous system consists of a four- 
lobed brain and a pair of large lateral nerves (Fig. 332} extending to 
the hinder end of the body, where they join; a dorsal median nerve is 
also usually present and in some species a ventral median one as well. 
A pair of lateral ciliated canals called the cerebral organs because they 

Fig. 333 — Diagram of nemertnn 

J -— Tet A, with pro- 

B, wits proboscis 
from Boas). 1, 
acta; 3, poltoD 



; G, gonads. 


lie in close relation to the dorsal cerebral lobes occur in most nemer- 
teans: these are represented by a pair of lateral sensory grooves in 
many paleonemerteans. In the hoplonemerteans and some heteronemer- 
teans also occur one to three supraoral or frontal organs, which are 
sensitive protuberances capable of being retracted so as to form a pit. 
Simple ocelli, each with lens and nerve, occur in most nemerteans. 
The number of such ocelli, which in a few forms are scattered along the 
sides of the body, may exceed 200. A few species have auditory sacs. 
The muscular system is well developed, consisting of two or three layers 
of circular and longitudinal muscles which bear an intimate relation to 
the main nerves. 

Most nemerteans are unisexual, but a few are hermaphroditic The 
gonads are paired, spherical organs, which usually lie between the intes- 
tinal diverticula (Fig. 333) and discharge their products directly through 
the body wall to the outside, no permanent genital ducts being present* 
A few are viviparous. Development is direct in many forms, while in 
others the young animal leaves the egg as a free-swimming larva 
(pilidium or Desor's larva) and passes through a complicated metamor- 
phosis before acquiring the form of the parent. 

History.— The Nemertea have only quite recently been given an inde- 
pendent systematic position, having been formally grouped with the 
Turbellaria. The name originated with Cuvier, who in 1815 gave the ge- 
neric name N emeries to Linens longissimus. Johnston (1846) first employed 
the name for the entire group. At the present time it is a matter of dis- 
pute whether the Nemertea should be grouped with the Plathelminthes or 
be given an independent position. The modern classification is due princi- 
pally to Hubrecht and Burger. The class contains over 400 species 
grouped in 4 orders, 87 species having been found on our Pacific and 62 
species on our Atlantic coast 

Key to the orders of Nemertea: 

Ox No sucking disc present; intestine not convoluted. 
bx Proboscis without stylets ; mouth behind brain ; intestinal caecum absent. 
Ox Muscular walls of body usually in 2 layers; eyes usually absent. 

1. Paleonemebtea 
c, Muscular walls of body in 3 main layers ; eyes usually present. 

2. Hetebokemebtea 
o, Stylets usually present; mouth in front of brain; intestinal caecum 

usually present 3. Hoflonemebtea 

o, Sucking disc present ; intestine convoluted 4. Bdellonemebtea 

Order 1. PALEONEMERTEA. (Protonemerttni; Mesonemertini.) 

Body long and slender, often filiform; mouth usually far back, being 
always behind the brain; proboscis without stylets; cerebral organ and 
eytos usually absent; body wall contains two muscle layers, an outer 


circular, an inner longitudinal, to which a third, an inner circular, is 

sometimes added; lateral nerves either external to the muscles or 

imbedded in the longitudinal layer; cutis absent: 4 families, all marine. 

Key to the families of Pdleonemertea here described: 

Ox Paired intestinal diverticula absent 1. Cabinellidae 

a t Paired intestinal diverticula present 2. Cephalotrighidax 


Cerebral organs represented by a pair of lateral epithelial depres- 
sions; brain and lateral nerves lie in the outer epithelium or just 
beneath it; mid-dorsal blood vessel usually absent; inner circular muscles 
encircling the proboscis sheath and intestine very thick: 5 genera and 
about 27 species. . 

Oabivella Johnston. Body cylindrical and filiform, with the head 
end large and distinctly set off; intestinal diverticula absent; lateral 
sense organs usually present near the paired excretory pores, consisting 
each of a round ciliated depression : 16 species, principally on the Pacific 

0. pellucida* Coe. Body very small, whitish in color, up to 25 mm. 
long and .5 mm. thick : not uncommon among annelid tubes at low water 
and below in Long Island and Vineyard Sounds; California. 


Body long and very slender, usually filiform; cerebral organ and 
eyes usually absent; mouth behind the brain; body wall contains two 
muscle layers, an outer circular and an inner longitudinal, with the brain 

and longitudinal nerves lying in the latter layer: 2 
genera and about 12 species. 

1. Oefhalote&ix Oersted. Body filiform, taper- 
ing at the forward end, which is pointed; no excre- 
tory canals; inner circular muscles absent; the worm 
coils the body in a spiral: about 7 species. 

0. linearis (Rathke) (Fig. 334). Body whitish, 
c ^llaiothri* yellowish, or flesh color, up to 15 cm. long and 1 mm. 
linearis (VerriU). thick; mouth very far back; proboscis very long and 

slender: Long Island Sound to Nova Scotia; Pacific 
coast; Europe; often common between tide lines, under stones and in 
the sand; breeds in August at Woods Hole. 

2. Oakivoxa Oudemans. Body rather thick, cylindrical in front, 
flattened behind: 4 species. 

* See "Descriptions of Three New Species of New England Paleonemerteans," 
by W. B. Coe, Trans. Conn. Acad., Vol. 9, p. 615, 1895. 


0. tremaphoros C. B. Thompson. Body 12 cm. long, 3 mm. thick, 
bun! in color; head white, flattened, rounded in front: Woods Hole. 

Order 2. HETEBONEMEBTEA. (Schizonemeetea.) 


Body often very long; mouth behind brain; proboscis without 
stylets; cerebral organ present; a caudal cirrus sometimes present; body 
wall contains three muscle layers of which the outer is longitudinal and 
between which and the circular muscles are the lateral nerves; cutis well 
developed : 2 families and over 170 species. 


Body usually very long, but in some species relatively short and 
thick; a pair of conspicuous lateral sensory grooves usually on the head; 
3 muscle layers in proboscis; the outer one being longitudinal; cephalic 
gland small and slender: 10 genera and about 150 species. 

Key to the genera of Lineidae here described: 

Oj Caudal cirrus not present. 

b x Lateral sensory grooves wanting 1. Pabapolia 

b t Lateral sensory grooves present 2. LlNKtrs 

a, Caudal cirrus present. 

6j Lateral sensory grooves wanting 3. Zygeupolia 

b t Lateral sensory grooves present. 

Ct Lateral body edges not thin; animals cannot swim 4. Miobura 

c, Lateral body edges very thin ; animals swim 5. Cerebbatulus 

1. Pabapolia Coe. Body cylindrical anteriorly, flattened poste- 
riorly; head not set off from body; without sensory grooves on the head; 
eyes not present; cerebral organs a pair of flat 

elevations: 1 species. S ^ 

P. aurantiaca Coe. Color -orange; length 25 
cm.; width 10 mm.; thickness 4 mm.: Vineyard 
Sound, at low-water mark. WJy 11 & 

2. Lnrarrs Sowerby. Body extremely long and 
filiform or tape-like and very contractile; head 
somewhat wider and tapering to a point; usually 
with eyes : about 50 species ; cosmopolitan ; animals 
cannot swim, and usually twist themselves into an 
irregular mass. 

L. ruber (O. F. Miiller) (L. gesserensis O. F. ^"^ p. 335 
MfiL; L. viridM Johnston) (Fig. 335). Body u T^^^S^ xx l' 
cylindrical ; color very variable, being green, brown, J™* 8bowlng ,ateri " 


or reddish ; a single row of 4 to 8 eyes on each side 
of head; 20 cm. or more; width 6 mm.: common under stones in shallow 
water from Long Island to Greenland; Alaska; Europe; breeds in June 
at Woods Hole. 



L. sodalis (Leidy). Body very slender and flattened, 25 cm. long 
and 5 mm. wide, green or brown in color; ventral side lighter than dor- 
sal ; a single row of 4 to 6 very small eyes on each side of the bead and a 
single pair of larger eyes some distance in front of the others : common 
from New Jersey to Bay of Fundy, living gregariously under stones, 
between tide lines; breeds in mid-winter in Long Island Sound. 

L. tricolor Verrill. Body small, 45 mm. long, 1.5 mm. wide, cylin- 
drical but somewhat flattened, dark green with a mid-dorsal yellowish 
stripe; with a single row of 8 to 14 eyes on each side: among algae and 
hydroids in shallow water in Vineyard and Long Island Sounds; very 
common in certain localities. 

3. Ztgeutolia C. B. Thompson. Body cylindrical anteriorly and 
flattened posteriorly; head very long and pointed and without lateral 
sensory grooves; caudal cirrus 
present: 1 species. 

Z. rabens (Coe) (Z. UtoraUs 
C. B. Thorn.*). Body slender 
and 8 cm. long; head pure white; 
body whitish : coast of New Eng- 
land; southern California; on 
sand flats between tide lines. 

4. Hiosttka Ehrenberg. 
Small, flat, and soft nemerteans 
with a caudal cirrus, which can- 
not swim ; with 3 frontal organs ; 
Fig. 336 Fig. 38T often with many eyes : about 17 


M. coca Verrill. Body dark 
brown or yellow; 10 cm. long and 2 mm. wide; no eyes: Long Island and 
Vineyard Sounds, at low-water mark ; sexually mature in July and 
August at Woods Hole. 

M. leldyi (Verr.) (Fig. 336). Body thick anteriorly; flattened pos- 
teriorly; 15 cm. long and 4.5 mm. wide; red or purple dorsally, usually 
with a lighter median line and lighter vent-rally; proboscis flesh color: 
common from New Jersey to Cape Ann in the sand near low-water mark; 
breeds in mid-summer. 

5. OaBEBUTtrxTTS Renier. Body long, flat, and broad, with a small 
pointed head and thin edges well adapted for swimming; eyes usually 
absent; mouth a long slit; with 3 frontal organs; proboscis very long; 
a caudal cirrus at hinder end: over 60 species; in all seas. 

r C. B. Thompson, Proc Acad. Nat ScL, PblUu, 


0. lacteus* (Leidy) (Fig. 337). Body 2 m. or less long and 25 mm. 
wide; extreme length up to 6.5 m.; flesh color; proboscis white: very 
common in the sand near low-water mark from Florida to Maine; breeds 
from March to May in Long Island Sound and in July in Casco Bay. 

Order 3. HOPLONEMERTEA. (Mbtanbmertinl) 

Body often very long and slender, but in many forms short and 
thick; mouth in front of the brain, usually coinciding with the opening 
of the proboscis; intestinal caecum present; proboscis provided with 
stylets (Fig. 333) ; lateral nerve cords internal to the muscle layers of 
the body wall; frontal sense organ present: 9 families and more than 
200 species, which live in the sea, in fresh water, and on land; a few 
species parasitic; development usually direct. 

Key to the families of Hoplonemeriea here described: 

Ox Proboscis does not reach the hinder third of the body.l. Bmplectonematidab 
o, Proboscis reaches almost to the hinder end of body. 
b x Four eyes usually present, forming a quadrangle. 
Cj Mostly hermaphroditic; long, thin worms, some terrestrial. 

2. Pbosobhochiodab 

c, Unisexual worms, short and thick 4. Pbostomatidae 

b* Eyes numerous 8. Amphipomdajc 


Body very long and thin; proboscis short 
and thick and with a single main stylet of 
variable form; usually with very small eyes: 5 
genera and about 25 species. 

1. Empucotohxxa Stimpson. Mouth and 
proboscis openings coincide ; usually with many 
eyes, never only four; accessory stylets pres- 
ent: 16 species. 

E. gradle (Johnston) (Fig. 338). Head 
end wider than body and with 20 to 30 eyes on 
each side; length about 20 cm.; breadth 1.5 
mm.; color green; stylets slender and curved 
at the end : very common on Pacific coast north w nemo ??«««» fC»»K 
of San Francisco, in shallow water; Europe. 

2. OAJtOTHOHBMEHTEst Coe. Body long and slender, cylindrical* 
usually not coiled; mouth and proboscis coincide, the latter being 

• See "On the Anatomy of a Species of Nemertean (Cerebratnlns lacteus Ver- 
rUl)," by W. R. Coe, Trans. Conn. Acad., Vol. 9, p. 470, 1805. "The Habits and 
Early Development of Cerebratnlns lacteus," by C. B. Wilson, Quart. Jour. Micros. 
84., VoL 43, 1000. 

f See "Nemertean Parasites of Crabs." by W, R, Qq^ Am, Nat % YqJ. 86* p. 431* 


rudimentary and without accessory stylets; 2 minute eyes: 2 species; 
parasitic on crabs. 

0. cardnophila (Kolliker). Body 15 mm. long when immature, and 
40 mm. long when mature; color red: on Portutnanus (Platyonichus) 
ocellatus of the New England coast and on Carcinus mcenas and other 
crabs of the European coast, being on the gills when immature and on 
the eggs when mature. 


Body long and thin, but rather broad ; 4 eyes usually present, form- 
ing a transverse quadrangle: 3 genera and 15 species; marine or 

Oeohexebtss Semper. Body slender and long, but of small size; 
proboscis as long as the body with a central and 2 or 4 accessory stylets; 
hermaphroditic or unisexual, viviparous or oviparous: terrestrial, occur- 
ring in subtropical islands, or imported into greenhouses; usually under 
stones or in rotting wood ; about 8 species. 

G. agricola (Willemoes-Suhm). Body 35 mm. long and 2 mm. wide, 
very variable in color, usually milk white, brownish, or greenish; 
hermaphroditic and viviparous: common near and in mangrove swamps 
in Bermuda. 


Body usually relatively short and thick; intestinal diverticula 
branched and usually not alternating regularly with the gonads; pro- 
boscis with a single central stylet with a conical base and several acces- 
sory stylets; cerebral organs large; usually numerous eyes: 3 genera 
and over 70 species; in all seas. 

Key to the genera of Amphiporidae: 

Ot Proboscis sheath without diverticula. 

b x Eyes extending posteriorly only to brain region 1. Amphipobub 

6 t Eyes extending posteriorly behind brain region 2. Zygonemertes 

a% Proboscis sheath with a small number of ventral diverticula. .3. Pboneubotes 

1. Amfhzporub Ehrenberg. Usually short and thick and very con- 
tractile worms which cannot swim or roll up spirally; with numerous 
eyes: over 70 species, including almost a third of all American 

Key to the species of Amphiporidae here described: 

Ox Body yellow A. ochbaceus 

a, Body white A. impabisfinosus 

a, Body red * » A. apgulatub 



Fig. 339 — Amphipo- 

rus ochraoeua 


A. ochraceus Verrill (Fig. 339). Body somewhat flattened, with a 

somewhat broader head; yellowish in color; 7 em. long and 3 mm. wide; 

eyes converging backwards: common between tide lines and beyond, 

under stones, etc., in Long Island and Vineyard 

Sounds; breeds in May and June. 

A. imparispinosus Griffin. Body small, 25 to 50 

mm. long; slender, slightly flattened posteriorly; 

white in color, sometimes with a reddish or yellowish 

tinge; ocelli in two groups on each side, converging 

anteriorly, less than forty in number: very common 

between tide lines, among algae, etc., on entire 

Pacific coast. 

A. angulatus (0. F. Miiller). Body stout with 

convex back; reddish or brownish in color; 15 cm. 

long and 8 mm. wide; head wider and set off from 

body, white in front with white spot on each side 

and an H-shaped figure in the middle; eyes nu- 
merous: common under stones between tide lines 

and beyond, from Cape Cod to Greenland; Puget Sound and north- 

2. Zygovemebtes Montgomery. Body long and slender; head 

broader than neck, with two pairs of lateral oblique 
furrows; ocelli very numerous, extending back along 
the sides of the body : 3 species. 

Z. virescens (Verrill) (Fig. 340). Body slender 
and rather fiat, usually light green in eolor, up to 4 
cm. long and 1.5 mm. wide; eyes numerous, in two or 
three parallel lateral rows along the side of the body : 
common between tide lines and beyond in Long Island 
and Vineyard Sounds; California. 

3. P&oveubotes Montgomery. Like Atnphiporu8 y 
but with 5 midventral diverticula in the proboscis 
sheath: 1 species. 

vim ^a ffb a j^ 

Zygonemertet P. multioculatus Mont. Body yellowish-brown in 

(Verrill). color with numerous eyes in two groups; 20 mm. long 

h\ 7oiward°end! and 3 mm. wide: New Jersey coast; between tide lines. 

Family 4. TETEAB' 



Body flat and slender or short and stout; 4 eyes usually present; 
intestinal diverticula and gonads alternate regularly; cerebral organs in 
front of the brain: 3 genera and about 75 species; in all seas, also in 
fresh water. 


Key to the genera of Tetrastemmidae: 

Ox Marine animals. 

ft, Body rather flat, soft in appearance 1. Tbtbastemma 

o, Body cylindrical, rigid in appearance 3. Oebstedia 

a, Fresh-water animals 2. Stichostemma 

1. TSTBASTHDIA Ehrenberg. Body small, with the 4 eyes forming 
a rectangle; occasionally each eye is double or represented by a group; 
cephalic gland large; mostly unisexual, occasionally hermaphroditic: over 
60 species. 

Key to the species of Tetrastemmidae here described: 

Ox Body slender, 
fct Body widest at forward end, tapering to hinder end. 

d Body whitish T. candiduic 

c% Body more or less spotted T. vebmiculum 

6, Body widest in the middle and tapering both ways T. elboans 

<h Body rather stout with dorsal stripes T. vittatum 

T. candidum (0. F. Miiller) (Fig. 341). Body very contractile and 
slender, white, light green, or yellowish in color, 2 cm. long and .5 mm. 

wide; head wide; hinder end tapering: common between 
tide lines and beyond, among algae, from Long Island 
Sound to Bay of Fundy; Europe. 

T. elegans (Girard). Body slender, tapering from the 
middle both ways; back with a median yellow and 2 lat- 
eral brown stripes, 2 cm. long, 1 mm. wide: among eel 
grass and on stones in Long Island and Vineyard Sounds. 
T. vermiculum (Quatrefages). Body slender, pale yel- 
low or reddish in color and more or less spotted; forward 
end broader than the hinder, 2 cm. long, 1 mm. wide: 
common on muddy bottoms between tide lines in Long 
Fig. 841 Island and Vineyard Sounds; Europe. 

T %Z°didZZ a T. vittatum (Verrill). Body rather stout, green or 

(Verriii). yellowish in color, sometimes with 1 or 2 dorsal stripes, 
5 cm. long, 4 mm. wide: common on muddy bottoms at low-water mark 
and beyond in Long Island and Vineyard Sounds. 

2. Stzohostekma* Montgomery. Similar to Tetrastetnma but with 
3 pairs of eyes; excretory organs extending the length of the body: 7 
species, in fresh water. 

8. rubrum (Leidy) (S. asensoriatum Mont). Body slender, 18 mm. 
long, yellow or reddish in color and very transparent, with 6, rarely 4 or 
8, eyes; preoral sense pit wanting; cephalic gland weak; hemaphroditic : 
Pennsylvania and Connecticut; eastern United States. 

* "The Habits and Natural Slstonr of Sticboatemma," by C. M. Child, Am. Nat, 
VoL 85, 1901. 



S. Owtzdia Quatrefages. Body cylindrical, of similar fonn at 
both ends, and rigid; 4 eyes forming a quadrangle; not over 15 mm. 
long: 4 species; marine. 

0. doraalii (Abildgaard) (Fig. 342). Bod; 10 mm. 
long and very slender; color variable, mottled with green, 
red, or brown : in shallow water on both the east and west 
coast of North America and in Europe, very common on 
piles and stones. 


Body short, flat, thick, and broad, with a large sucker 
at the hinder end; intestine without diverticula and con- 
voluted; proboscis without stylets, its opening coinciding 
with the mouth and almost as long as the body; no eyes 
or cerebral organ: 1 genus 
and 3 species, living commensally in the 
branchial chamber of marine and fresh- 
water mollusks; cosmopolitan. 

Malaoobdeixa Blainville. With the 
characters of the family: 3 species. 

M. grossa (0. F, Miiller) (Fig. 343). 

Hinder end of body broader than forward 

end; male 3 cm. long and S mm. broad, 

B gray in color; female 26 mm. long and 13 

Ft*. 343— Maiacobneua protta. mm. broad, yellowish or brownish in color: 

A, entire worm (Verrill). 1, , 

EroboadB ; 2, mouth ; 3, intra- in Mua arenana, Venus, and other pe- 
ae; 4, sucker. B, section , , ,,-,., 

through the forward end tBiir- Iecypods, on both sides of the north 

ger>. 1. month: 2, proboscis ; 

8, proboscis Bbenth. Atlantic. 


Roundworms. TJnsegmented, round worms, usually so elongated 
and Blender that they are called thread or hair worms, which are ento- 
paraaites in animals or plants or lead a free life in the water or in moist 
earth. The body is not ciliated and is without paired appendages and 
usually without external bristles, hairs, or suckers. With a very few 
exceptions all are unisexual. 

The snbphylnm contains 3 classes. 

• Bee "The Determination of Generic Types and a List of Round Worms Genera 
and Tbelr Original and TTpe Species," by C. W, Stiles and A. Haaaall, Bull. T9, Bur. 
of Ad. Ind.. Dept. of Ag., 1909. 



Key to the classes of Nemat helminthes : 

Ox No spiny proboscis at forward end ; intestine present. 

6 X Mouth and intestine not degenerate in adult; lateral lines present. 

1. Nematoda 

5, Mouth and intestine degenerate ; lateral lines absent 2. Gordiacka 

a, Spiny proboscis present ; no intestine 3. Acanthockphala 

Class 1. NEMATODA.* 

Threadworms (Fig. 344). Round, slender worms, usually white 
or flesh color in appearance, which vary from microscopic size to a 

meter in length. The integument consists of a cuticula 
which is usually smooth on the outer surface and a soft 
subcuticula; no hypodermis is present, but the subcuticula 
is supposed to represent it. There is a voluminous body 
cavity into which the subcuticula projects along the 
median dorsal and ventral and the two lateral lines, 
forming thus 4 prominent longitudinal ridges. In the 
lateral ridges run the paired excretory canals, which open 
to the outside by a pore just behind the mouth, and the 
lateral nerve cords; and in the dorsal and ventral ridges 
are also nerve cords. Lying next the subcuticula is a 
single layer of characteristic, longitudinal muscle fibers, 
no circular fibers being present. The nervous system con- 
sists of a nerve ring containing ganglion cells which sur- 
rounds the oesophagus and a number of longitudinal nerves 
extending both forwards and backwards, those going back- 
wards being joined by transverse commissures. The only 
special sense organs are simple eyes, which some nema- 
todes possess, and also sensory papillae. 

The body cavity is without mesenteries, transverse 
septa, or peritoneal lining and contains blood. Lying in 
it are the alimentary canal and the reproductive organs. 
The mouth is at the forward end of the body and may be 
surrounded by sensory lips or papillae, and armed with 
chitinous teeth. The oesophagus is a muscular sucking- 
organ into which a pair of long glands may open; its 
hinder end may be constricted, causing the formation of one or two 
swollen divisions, called oesophageal bulbs. The intestine is a straight 
tube which passes to the anus near the hinder end of the body. The 

* See "Monographic der Nematoden," by A. Schneider, 1866. "Die Sttsswasser- 
fauna Deutschlands," by U A. Jftgerekloid and O. von Llnstow, Heft 15. 1900. "The 
Nematodes Parasitic In the Alimentary Tract of Cattlo, Sheep," etc., by B. H. Ran- 
som, Bull. 127, Bar. An. Ind., 1911. 

Fig. 344 
Diagram of 



(Stlssw. F. 


1, month 

2, nerve ring 

3. oesophagus 

4, excretory 


5, Intestine 
6, ovary 

7, genital pore 
8, anus. 


animals are, with a few exceptions, unisexual, the females being larger 
than the males, with a genital pore near the middle or towards the for- 
ward end of the body. The genital organs are simply formed tubular 
structures. In the male the testis is usually a single tube which 
communicates with the rectum. Anal papillae are often present; long 
spicules also usually project from the anus of the male by means of 
which it attaches itself to the female; in the Strongillidae and other 
families an expansion of the hinder end called the bursa also serves the 
same purpose. The spermatozoa are short and tailless. In the female 
two genital tubes are present which meet near the external opening. The 
distal ends of these are ovaries and produce the eggs while the proximal 
ends act as uteri. The eggs of the various species have a characteristic 
appearance by means of which the animals may be identified (Fig. 345). 
Many nematodes are viviparous, the 
young animals developing in the uterus. 
Habits and Distribution.— Nematodes 
are mostly active animals which move by 
a peculiar whipping motion of the body. 
With the exception of certain minute 
forms which lead a free life in fresh ,?«\ 3 ^ E i PJf ya ? 7 D ? a ' 

todes (from ward). A, Ancylos- 

and salt water and in decaying organic fSSus ?°denaie ; b, Necator amer- 
matter, they are internal parasites of ^^ f ^J,£aS|S 
animals and plants, being among the 

commonest parasites of man and the domestic animals. Like most para- 
sites, many pass through a metamorphosis in their youth and may live 
in two different hosts. 

History. —Some of the commonest nematodes which are the cause of 
disease in man and his domestic animals have been known for a very long 
time and were much studied by the early zoologists. In 1808 Rudolphi 
created the orders Nematoda and Acanthocephala, and in 1851 Vogt 
formed a class of these two orders and the Gordiacea, which he called the 
Nematelmia. The most active investigators of nematodes at the present 
time in this country are the United States Department of Agriculture and 
the Marine Hospital Service. 

The class contains about 15 families and several thousand species. 

Key to the families of Nematoda here described: 

*! Mostly non-parasitic nematodes. 

Ox Marine and free-swimming nematodes 1. Enoplidae 

b % In fresh water or in the ground ; a few parasitic in animals and plants. 

2. Anguillulidae 
Oj Parasitic nematodes. 

b x Parasitic in invertebrates ; mouth with 6 papillae 3. Mebmitidak 

&j Parasitic in vertebrates. 


Ox Month not surrounded by 3 prominent lips. 
dt Body very long and filiform ; 4 pairs of papillae around the anna of 

male 4. Filabiidajc 

4b Anterior part of body with a very long and characteristic row of cells. 

5. Tbiohinellidae 

d, Male with a large bell-shaped bursa 6. Stbonoiudab 

*, Mouth surrounded by 3 prominent lips 7. Asoabidae 

Family 1. ENOPLIDAE. 

Minute, free-living worms, found principally in the sea, but also in 
fresh water or in the earth; mouth often surrounded by hairs and 
bristles; oesophagus without bulb; eyes often present; male with spicules: 
numerous species. 

1. Evoflus Dujardin. Body elongate, tapering behind; cuticula 
smooth; mouth with 6 papillae, behind which is a circlet of 10 to 12 
bristles: numerous species in both salt and fresh water. 

E. brevis Bastian. lives among algae and hydroids in shallow 
water; often greenish in color; length 5 mm. 

2. DoRYLAunrs Dujardin. Large worms; cuticula smooth, not 
ringed; extreme front end set off by a constriction; mouth with papillae 
and a large bristle: numerous species, which live at the roots of plants 
in moist earth and water. 

D. maximus Biitschli. Length 7 mm.: in garden earth. 


Minute worms which lead a free life in water or earth or decaying 
substances, or are parasitic in plants or (rarely) in animals; mouth with- 
out papillae; oesophagus with 2 bulbs; male with 2 spicules and some- 
times with a bursa: numerous genera and species. 

Key to the genera of Anguillulidae here described: 

Oi Free-living worms, in soil or decaying substances. 

h x Mouth with 2 or 3 teeth 2. Diflogasteb 

o, Mouth without teeth. 

Ct In vinegar or paste 1. Anguillula 

c% In the earth or decaying substances 3. Rhabditis 

Of Parasitic worms. 

\ Parasitic in plants ; a spine in the mouth. 

Ct In the roots of vegetables 4. Hetebodeba 

©, In wheat b\ Tylenchtjs 

o, Parasitic in animals. 

Ox In the bumble bee 5. Sphjebulabia 

o, In man 7. Strongyloses 

• See "Helminthological Contributions," No. 2, by J. Leidy, Proc. Acad. Nat. Sd. t 
Fblla., Vol. 6, p. 224. "Monograph of the Anguillulidae," by H. C. Bastian, Transact. 
Linn. Soc, London, Vol. 25, 1866. "On the Family Anguillulidae," etc., by J. Leidy, 
Proc A. N. 8., PhlUu, Vol. 22, p. 68, 1870. 



Fig. 346 

Diplogaster rivalto 

(Stlssw. F. Dent.). 

A, whole worm 

B, head. 

1. AnatriLLTTLA Ehrenberg. Cuticula smooth and ringed; body elon- 
gate, tapering behind; vulva behind the middle; spicules long; no 
bursa: several species. 

A. aceti (0. F. Miiller). Vinegar eel. Length 2 
mm.: in vinegar, living on the fungus forming the 
11 mother/' also in stale paste; has also been found in 
the human bladder. 

2. Diplogasteh M. Schultze. Body elongate; 
cuticula ringed and often ridged; body tapering be- 
hind ; mouth with 2 or 3 teeth and often with papillae 
around it; male with or without bursa: numerous 
species; in fresh water, earth, and decaying sub- 

D. rivalis Ley dig (Fig. 346). Length 2 mm.; 
bind end tapering to a long, fine point; mouth sur- 
rounded by a membrane around which are 6 short bristles: viviparous; 
common in ponds and streams. 

3. Rhabdxtis Dujardin. Minute worms living in decaying sub- 
stances or the ground; head end often constricted: 
mouth triangular, usually with 3 to 6 lips; body 
slender, ending with a point; male with 2 short 
spicules: many species. 

E. terricola Duj. Body without distinct rings, 1.4 
mm. long; mouth cavity long, with 2 ring-shaped thick- 
enings at its base: common. 

4. Hetebodeba Schmidt. Minute worms infecting 
the roots of various plants, with a spine in the mouth 
for piercing plant tissues: 1 species. 

H. schachti* Schmidt (H. radicola 0. F. Miiller) 
(Fig. 347). Male 1.5 mm. long, .045 mm. thick; female 
1 mm. long and viviparous, being .5 mm. thick when 
full of young: in the roots of various vegetables and 
other cultivated plants, causing swellings. 

5. Sfkbbulabxa Dufour. Minute worms, free- 
living and parasitic; male with a bursa; mouth with a 
tooth: 1 species. 

8. bombi Duf. The young animals, about 1 mm. 
long, live in the earth; after pairing, the fertilized 
females migrate into the body of a hibernating queen bumblebee; here 
the uterus, filled with growing larvae, evaginates out of the vulva and 

Fig. 347 
(Stone and 
1, pharynx ; 2, 
intestine ; 3, ex- 
cretory pore ; 4. 
genital pore and 
anus; 5, testes. 

• See "Nematode Worms in the Greenhouse," by G. B. Stone and B. B. Smith, 
Bull. No. r>5, Hatch Bxp. Sta, of Mass., Ag. CoL, 1898. 



grows until it is many times the size of the rest of the worm, reaching 
a length of 15 mm. ; the young larvae are born in the bee. 

6. Ttlenoeub Bastian. Cuticula ringed; body tapering to a point 
behind; mouth with a spine for piercing plant tissues; vulva much back 
of the middle: numerous species, which are parasitic in plants. 

T. tritid Bast. Male 2 mm., female 4.5 mm. long and spirally 
rolled together; color yellowish: in wheat, in a grain of which. several 
larvae may live; when the wheat is sown the larvae migrate into the 

young plants and finally become mature in the buds; 
the eggs are laid here and the young larvae migrate 
into the ripening grain and remain there; they can lie 
in dried wheat for years without dying. 

7. Stbongyloides Qrassi. Minute worms with 
heterogony, a non-parasitic, unisexual generation alter- 
nating with an hermaphroditic parasitic generation, the 
former having a very long cylindrical oesophagus, the 
latter with a short oesophagus with a bulb; no teeth 
and 2 spicules present: 1 species. 

8. stercoralis* (Bavay) (Fig. 348). Hermaphro- 
ditic form (S. intestinalis Bavay) 2.2 mm. long and 
.034 mm. wide, with an oesophagus a quarter as long as 
the body ; vulva in the hinder part of the body : it lives 
in the human intestine and causes Cochin China diar- 
rhoea, having been first observed in that country; a few large eggs are 
produced, from which hatch rhabditiform larvae, which are about .3 mm. 
long; they pass out with the feces and develop into the unisexual form, of 
which the male is .7 mm. and the female is about 1 mm. long, and which 
lead a free life; from their eggs the parasitic generation develops; in 
this country and Europe only the parasitic generation is known. 

Fig. 848 
A, hermaphro- 
ditic form 
B, larva. 

Family 3. MEEMITLDAE. 


Hairworms. Body long and filiform; mouth with 6 papillae; adults 
without anus; hinder part of the intestine solid; male with 2 spicules 
and 3 rows of papillae: the young animals live in the body cavity of 
insects, especially caterpillars, grasshoppers, and beetles, and occasion- 
ally spiders and snails or crayfish, from which they migrate into the ground 
or the water; here they become mature and lay their eggs; 1 genus. 

MERXiBt Dujardin. With the characters of the family: several 

• Bee "Occurrence of Strongyloses Intestinalis In the United States/* by M. L. 
Price, The Jour, of the Am. Med. Asso., Vol. 41, 1903. 

t See "Observations," etc., by J. Leldy, Proc. A. N. 8., Phlla., Vol. 5, p. 202. 
"A Synopsis of Bntozoa," etc., by same. Ibid., Vol. 8, 1866, p. 422. 



M. nigrescens Doj. (Fig. 349). Body 12 cm. long, .5 mm. thick, 
attenuated anteriorly and blunt behind; color white, with the black 
ovary showing through; the young worms migrate on warm 
summer days from the body of their hosts, often in large 
numbers, into the moist earth, causing a belief that they 
have rained down. 

Family 4. FLLABIIDAE.* 

Fig. 349 



( Bliss w. F. 


Body very long and filiform; mouth often surrounded 
by papillae or by 2 lips ; no oesophageal bulb ; male with 1 

spicule or with 2 of unequal size and with a spiral twist 
of the hinder end; usually viviparous: several genera. 
Fzlabza 0. F. Miiller. Vulva towards the forward 
end; male with 2 spicules, and much smaller than the 
female: numerous species, which live in man and other 
vertebrates as final hosts, and probably in insects or crusta- 
ceans as intermediate hosts; Leidy mentions over 30 species 
in this country. 

F. immitisf Leidy (Fig. 350). Length of male 18 cm.; 
thickness .9 mm., with a corkscrew hinder end; length of 
female 30 cm. ; thickness 1.3 mm. : in the heart and veins of 
the dog, the .28 mm. long larvae appearing in the blood, 
especially in the night time ; the larvae are transferred from 
one dog to another by mosquitoes; very common in China 
and Japan, and occurring in America and Europe ; it some- 
times infects man. 
F. bancrofti Cobbold (Fig. 351). Male 
4 cm. long, .1 mm. thick and colorless; 
female 8 cm. long, .28 mm. thick and 
brownish in color: in the heart and lymph 
vessels of man in the tropics, also in the 
southern United States, the .3 mm. long 
larvae appearing in the blood, but in the 
surface circulation only at night ; the larvae 
are transferred from one person to an- 
other by mosquitoes; one of the causes of 

F. loa (Cob.). Male 30 mm. long, .4 mm. thick, with 8 large cir- 
cumanal papillae; female 41 mm. long and .5 mm. thick; body with 

* See "The Zoological Characters of the Roundworm Genus Filaria," etc., by 
C. W. Stiles, Bull. 84, Hygienic Lab., etc., 1907. 

t See "Notices of Nematoid Worms," by J. Leidy, Proc A. N. S., Phila., 1886, 
p. 308. 


Fig. 350 



(from Braun). 

A, male 

B, female. 

Fig. 361 — Filaria bancrofti 

(from Braun), showing 

several worms among 

blood corpuscles. 


numerous small protuberances, irregularly distributed: beneath the con- 
junctiva of the eye, in the eyelid, or in the subcutaneous tissue of other 
parts of the body in man; on the west coast of Africa and occasionally 
in America and Europe. 

P. medinensifl (L.). Medina or Guinea worm. Length of female 
2 m or less; thickness 1.7 mm.; color white or yellowish; intestine 
atrophied; male not known: in the subcutaneous tissue of man, espe- 
cially in the legs, also in domestic animals, producing a sore which 
breaks to the outside, freeing the embryos; the young are found in 
Cyclops and are probably conveyed with drinking water into the human 
body; in Africa and other tropical countries, and supposed to be the 
"burning fiery serpents" which troubled the children of Israel in the 


Elongated worms with the forward portion attenuated, often ex- 
tremely so; mouth without papillae or teeth; oesophagus slender, without 
bulb, and very long, in some cases being half as long as the body, and 
situated beneath a very characteristic row of conspicuously large cells; 
male with 1 spicule or none; female with but 1 ovary: 3 genera and 
numerous species, all internal parasites. 

Key to the genera of Trichinellidae : 

Ox Forward portion very slender ; whip worms 1. Thichubis 

a, Forward portion not whip-like. 

& & Male without spicule 2. Tbichinella 

b t Male with spicule 3. Tbiohosoka 

1. Tbiohtois Roederer (Trichocephalus Goeze). 

a \ PT aJ R Body made up of 2 portions, a very slender forward 

^ portion, containing the oesophagus, and a thick hinder 

portion, containing the reproductive organs; hinder 

end of male rolled up and with spicule; vulva at the 
forward end of the thick portion : in the large intes- 
tine, especially the cecum, of mammals; development 
direct, infection resulting from swallowing the eggs; 

Trichvrti trichiura 1 species. 

a, femafe; r Bl n inaie, T. trichiura* (L.) (Trichocephalus dispar Bu- 

end imbedded in dolphi) (Fig. 352). Whip worm. Male 45 mm. long; 

mucous mem- female 50 mm. long; eggs (Fig. 345, E) ellipsoid, .05 


mm. long and .023 mm. thick : in man, cosmopolitan ; 

perhaps the commonest intestinal parasite in man and often the indirect 

cause of appendicitis and typhoid fever. 

* See "A Statistical Study of the Prevalence of Intestinal Worms In Man," by 
C. W. Stiles and P. B. Garrison, Bull. No. 28 of Hygienic Lab., 1906. 


2. TaiOKtSSLLA Railliet (Trichina Owen). Minute worms, with the 
forward portion not much slenderer than the hinder; male without spic- 
ule but with 2 conical projections at hinder end; viviparous; anus 
terminal: 1 species. 

T. spiralis" (Owen) (Fig. 353). Male 1.5 nun. long; female 3.5 mm. 
long; young bom alive: in the small intestine of man, the pig, rat, and 
other animals. The young worms, which are about .1 mm. long, are the 
cause of trichinosis. They bore their way 
through the intestinal wall of the host and 
migrate in the blood and lymph to the muscles, 
where they encyst themselves and frequently 
so lame the muscles of the jaws, neck, and 
thorax that their functioning is interfered with 
and death may ensue. If meat containing the 
cysts be eaten by another animal or a person 
the worm is released and passing into the in- 
testine quickly becomes mature. Man gets the 
infection by eating insufficiently cooked pork 
containing the cysts; the pig gets it by eating 
offal or rats. The rat is supposed to be the 
original host of the worm. 

3. TaiOHoaoKA RudolphL Body hair-like, 
the forward portion not much slenderer than 

the hinder; usually a single spicule present: rJ^' (u^ 1 ^^? ^ 
in birds and mammals ; numerous species. oVpori * 

T. tenulssimum Diesing. Male 10 mm. 
Ions;; female 17 mm. long: in duodenum of ova°y;'\ l a£me; e o, n te3tis! 
the pigeons. 

T. craailcaadnm Bellingham. Female 17 mm. long; forward end 
rounded and with small protuberances back as far as the vulva; male 
2.5 mm. long, without spicule, and lies often in the female vulva: in the 
liver and other organs of the rat. 


Month surrounded by several papillae; no oesophageal bulb; hinder 
end of male expanded to form a broad bursa (Fig. 355, B), also with 
1 or 2 spicules : numerous genera and species which live in the intestine, 
lungs and other organs of vertebrates, especially mammals. 

" by C. W. Stiles, Bull. No. 30, Barest) of AH, 

88. ' 


Key to the genera of Strongylidae here described : 

Ox Bursa well developed. 

b x Buna without ribs ; 1 spicule 1. Diootofhyiob 

6, Bursa with ribs; 2 spicules. 
Cj Mouth small, without teeth. 

dx Male and female not permanently attached 2. Dictyocaulus 

df Male and female permanently joined together 3. Syngamus 

e% Mouth large, with teeth. 
dx Without oral glands. 

^ Without ventral teeth but with cutting plates 4. Nbcatob 

e, With ventral teeth 5. Anchylostoica 

d, Two long oral glands 6. Strongylus 

o. Bursa small ; in fishes 7. Cucullanus 

1. DlOOTOPHTME Collet (Eustrongulus Diesing). Large worms with 
6 prominent oral papillae; bursa without ribs; 1 spicule present; vulva 
near forward end: 1 species. 

D. renale (Goeze) (D. gigas Rudolphi) (Fig. 354). Body generally 
blood red; male 40 cm. long or less and 6 mm. thick; female 1 m. long or 

less, and 12 mm. thick; egg (Fig. 345, A) ovoid, brown, 
and about .068 mm. by .04 mm. : in the kidney of the dog 
and other domestic animals as well as rarely in man. 

2. Dxotyooaulto Railliet and Henry. Mouth with 6 
small papillae, bursa large with ribs and two spicules; 
female genital pore behind the middle: many species. 

D. fllaria (Rudolphi). Body white and thread-like, 
from 3 to 10 cm. in length ; egg about .12 mm. by .06 mm. : 
in the bronchi of sheep and goats, causing often a dan- 
gerous bronchitis. 
Fig 354 *"*• ra ^ e8cen8 (Leuckart). Body brown and thread- 

Dioctophpme ^ e f from 18 to 35 mm. long; egg about J. nun. by .06 
(from^ward). mm. : in the bronchi and lungs of sheep and goats, causing 

often pneumonia. 

3. Syhgaxto von Siebold. Male permanently attached by the 
bursa to the vulva of the much larger female, which is forward of the 
middle, forming together a Y-shaped object; bursa ribbed: 1 species. 

8. trachealis v. Sieb. Body red; male 6 mm. long; female 20 mm. 
long: in the trachea of fowls, causing gapes. 

4. Negator Stiles. Head end narrower than body and curved 
dorsally; mouth large, opening obliquely into a chitinous buccal capsule, 
the dorsal portion of which is shorter than the ventral; buccal cavity 
has ventrally a pair of prominent semilunar cutting plates or lips and 
dorsally a pair of smaller lips and a conical tooth projecting into it; a 
large bursa with 2 long, barbed spicules : 2 species, in man and anthropoid 


N. amerlcanus* (Stiles). American hookworm (Fig. 355). Male 9 
mm. long; female 11 nun. long; vulva in forward half of body; eggs 
(Fig. 345, B) about .07 mm. long by .038 mm. broad: in the small intes- 
tine of man and the gorilla, where it moves about sucking blood, causing 

showing bursa (Stiles). 

1, ventral cutting lips. 

often a severe anemia; very common in the South among the poorer 
classes; the eggs pass out with the feces, the young worms living in the 
moist earth; infection may be got by drinking infected water, by eating 
infected substances, and even as the result of the migration of the young 
worms through the skin of feet or bands. 

5. Amohtlostoju, Dubini. Similar to Neca- 
tor bat with head end not narrower than body I 

and with 2 pairs of large ventral-curved teeth 
and a pair of dorsal teeth in place of the cutting 
plates, directed forwards ; vulva in hinder half of 
body; 5 species. 

A. duodenale Dub. (Figs 345, A, and 356). 
Old World hookworm. Length of male 9 mm.; 
of female 12 mm.: in man, in Europe and Asia, 
occasionally in America. 

A. caninum (Ercolani). Similar to the above 
but somewhat larger: common in dogs and cats and often fatal to young 

S. Stbongyxds O. F. Muller. Similar to Anchyloatama but with 
two long glands opening into the mouth, around which are small flat 
spines: numerous species. 

• Bee "Report upon the Prevalence and Geographic Distribution of the Hoot- 
worm Disease In tbe United States," by C. W. Stiles, Bull. No. 10, Hygienic Lab., 
Treas. Dept, 1903. "llndnarlaali in the South," by C. A. Smith, Tbe Jour, of tbe 
Am. Med. Aesc, Vol. 41, p. 70S, 1903. "Tbe Anatomy and Life History," etc, by A. 
Loom, Records of School of sled., Cairo, 1S11, 

Fig. 386 
Anohylottoma dnodenale 
— dorsal view of bead, 
showing teeth ( Loots) . 
1, ventral teeth. 


8. equinus MiilL The armed palisade worm. Male 20 to 30 mm. 
long; female 23 to 55 mm. long, 2 mm. thick; body red or brown, straight 
and rigid ; mouth with small teeth ; egg .09 by .05 mm. : common in the 
caBcum or colon of the horse, causing colic; the young worms live in 
water and moist earth and pass directly in drinking water into the 
horse; they are also found in the abdominal arteries where they cause 

7. Ottcttllantts 0. F. Miiller. Small worms with 2 lateral chitinous 
plates on the head and with rudimentary bursa; mouth ridged longi- 
tudinally; male with a spicule; vulva in the middle of the body: several 

0. elegans Zeder. Male 8 mm. long; female 13 mm. long; body 

yellowish or reddish; mouth with 6 papillae: in the intestine of the 

perch and other fish. 

Family 7. ASCABIDAE. 

Body often rather stout and large; mouth surrounded by 3 promi- 
nent lips, 1 dorsal and 2 ventral; oesophagus with 1 or 2 bulbs; hinder 
end of male spirally curved and usually 1 or 2 spicules project from the 
anus: several hundred species, almost all intestinal parasites in 

Key to the genera of Ascaridae here described : 

Ox Large nematodes with prominent lips 1. Asgabis 

a, Small nematodes with usually small lips. 

b Y Male with a sucker before the anus 3. HETEBAKifl 

ft, No sucker present 2. Ozyubis 

1. Asoabxb L. Large worms in which the 3 lips are set off by a 
constriction, forming a distinct knob at the front end of the body; 

oesophagus without distinct bulb; male with 2 
equal spicules and numerous ventral caudal papil- 
lae: several hundred species, which live in the 
intestines of birds and mammals. 

A. lumbricoides L. Eelworm (Fig. 357). Male 

»^7&£fiM. 15 t0 25 cm ' long ' 3 ^ thick 5 female 20 to « 
Bl dori e i r ^et°o f f , ?r a oS{ cm - lon ^ 5 mm - thick 5 *& (**• 345, C) brown, 
fro d ni endT entrEl VleW ° f with rou g hene d surface, about .06 mm. by .05 

mm.; body with the appearance of an earth 
worm : in the small intestine of man and domestic animals, sometimes in 
considerable numbers, especially in children, when they are dangerous 
parasites; occasionally found in the liver, trachea, and other organs; 
development direct, the eggs pass out with the feces, and the young 
larvae develop in water or moist earth ; infection is got in drinking water 
QX from the ground or from the skin of raw fruits. 


A « b 



Fig. 358 
Aacaris oanis. 
Cross section 
showing fins 
(from firann). 

A. aquorum Goeze (A. megalocephala Cloquet). Maw worm. Length 
15 to 37 cm.; thickness 8 to 12 mm.; eggs spherical, .1 mm. in diameter: 
in the small intestine of the horse, often in large num- 
bers, when it is a dangerous parasite. 

A. cuds (Werner) (A. mystax Zeder) (Fig. 358). 
Male 6 cm. long, 1 mm. thick; female 18 em. long; a 
pair of fin-like projections on the sides of the head; 
eggs (Fig. 345, D) almost spherical, about .07 mm. in 
diameter: in the ■ intestine of cats and' dogs, usually 
common, occasionally in man; development direct. 

2. Oxytoxs Rudolphi. Small worms in which the 3 lips are more 
or less indistinct; oesophagus long, with & bulb followed by a dilated 

portion ; hinder end of male very short with but 1 spic- 
ule; vulva in forward half; hinder end of female taper- 
ing to la sharp point: about 15 species; in the large 
intestine of vertebrates, also in certain insects. 

O. vennicularis (L.). Pin worm (Fig. 359). Female 
10 mm. long; .6 mm. thick; male 4 mm. long; a dorsal 
and a ventral cuticular projection on the head; egg 
(Fig. 345, F) .05 mm. by .02 mm.: in the large intes- 
tine, also occasionally in other parts of the digestive 
tract of man, especially of children; often the indirect 
cause of appendicitis; development direct, the eggs of 
the females being taken in with drinking water or 
directly from the hands. 

3. Hztzsaxis Dujardin. Lips as in Ascaris; male 
with a large sucker surrounded by 4 papillae before 
the anus and 2 lateral thickenings; oral papillae small: 
numerous species. 

H. vascularis Froehlioh. Length 7 to 15 mm.; tail 
of male with 5 preanal and 7 postanal papillae; no teeth 
in mouth: in the large intestine of chickens and ducks. 
H. brevicauda (Zeder). Length 5 mm.; mouth surrounded by 10 
papillae: in the intestine of frogs and toads. 

Fig. 860 



(from Braan). 

A. female 

B, male. 

1, ceeophaguf 

2,TnlTa; 8, anna. 

Class 2. GORDIAOEA.* 

Hair worms. Long and very slender worms of the same diameter 
throughout and never sharply pointed behind, which are sometimes found 

* 8ee "The Gordlacea of Certain American Collections/' by T. H. Montgomery, 
BolL Mas. Comp. Zool., Harvard, Vol. 32, 1898. Ibid., by the same, Pt. 2, Proc 
CaL Acad. C. 8d., 8rd Ser., Vol. 1, 1898. "Synopsis of the Gordlacea," by the same. 
Am. Nat, VoL 88, p. 647, 1899. 


wriggling actively in fresh-water ponds and ditches, and look much like 
thick horsehairs. Sometimes a number are found in a tangled mass, a 
feature which suggested the name of the typical genus. As larvae the 
worms live in the body cavity of insects, whence they migrate into the 
water, their sudden appearance often giving rise to the common belief 
that they are metamorphosed horsehairs. 

The integument consists of a thick cuticula and a hypodermis, the 
latter being a single-layered epithelium and very different from the sub- 
cuticula of nematodes. Beneath the integument is a muscle layer consist- 
ing of a single layer of longitudinal muscle cells. The body cavity is 
lined with a peritoneum and traversed by dorsoventral mesenteries and 
is nearly filled with a mass of connective tissue cells forming a sort of 
parenchyma. The mouth and oesophagus in adults are closed and the 
intestine is a straight tube proceeding to the anus at the hinder end of 
the body. Special respiratory, circulatory, and excretory organs are 

The nervous system consists of a nerve ring round the oesophagus 
with two dorsal swellings and a median ventral cord. The sense organs 

are a pair of eyes and numerous tactile bristles. The 
sexes are separate; two testes and two ovaries are 
present and in both sexes the reproductive organs open 
to the outside through the anus. 

The eggs are laid in long strings in the water, the 
GorSfc/iarva length of one observed by Leidy being 91 inches, and 
*i£|5at). F " containing 6 million eggs. The young larvae (Pig. 
360), after hatching, seeks some aquatic insect larva 
into which it bores its way by means of bristles on the head. It remains 
here in the muscles or fat body until the insect is eaten by some other 
water insect or fish or has completed its larval life and left the water as 
an adult If in the latter case the host is eaten by a predaceous beetle 
the larval worm may pass into its second larval stage in its body cavity, 
or in It grasshopper or other insect if the first host dies and the young 
larva falls upon the ground. In its second host the worm grows rapidly 
and assumes the long hair-like form of the adult, and finally breaks its 
way through the body wall of its host and falls into the water or is swept 
there by the rain, where it becomes mature. 

The class contains 2 families and about 15 American species. The 
second of these families is very different from the first and its relationships 
are rather obscure. 

Key to the families of Gordiacea: 

Oi Fresh-water and terrestrial worms 1. Gobdiidae 

o, Marine worms 2. Nectonematidae 


Family 1. GORDHDAE. 
With the characters of the order : 4 genera. 
Key to the genera of GordUdae here described: 
o, Hinder end bilobed or trilobed. 
b, Hinder end bilobed and rolled spirally. 

c, Head end not obliquely truncated 1. Gordtob (male) 

c. Head end obliquely truncated 2. Pabaoobdius (male) 

b. Hinder end trilobed 2. Pabagobditjs (female) 

a, Hinder end not forked. 

6, Hinder end rolled spirally 3. Gbokdodeb (male) 

6, Hinder end not rolled «pir*Uy. 

o, Hinder end not swollen 1. GOBDITJB (female) 

c, Hinder end swollen and knob-like 3. Chobdodes (female) 

1. GoBSnm L. Hair worms with a forked and spirally rolled tail 
and often a V-shaped ridge behind the anas in the male, and a straight, 
unf oiked tail in the female : about 10 species. 

&. aquation* L. (G. robvttus Leidy) (Fig. 361). Length 28 to 89 
em.; thickness .5 to 1 mm.; color white or brown; ends blunt; V-shaped 
postanal ridge in male: cosmopolitan. 

Fig. soa Fig. 803 

Fig. 381 — QoraUf aqtiatio%»; hinder end of male (Montgomery). Fig. S63 — 
Qordlut Uneattit; hinder end of mate (Montgomery). Fig. 863— ParaoonHut varHM; 
Under end of female (A) sod male (B) (Montgomery). 

0. linoatns Leidy (Fig. 362). No distinct V-shaped ridge behind 
the anus, on each side of which in the male is a longitudinal line of 
hairs; color yellowish-white; female with longitudinal rows of cuticular 
areoles: eastern states. 

3. Pasagordius* Camerano. Hair worms with a forked and spirally 
rolled tail in the male, and a trilobed tail in the female: 1 species. 

P. Tarius (Leidy) (Fig. 363). Length 10 to 30 cm.; head of male 
obliquely truncated; the commonest gordian: occasionally occurs in 
human digestive tract; North America, 

3. Orokdosxb Mobius. Hair worms with the hinder end spirally 
rolled and not forked in the male, but not rolled and with a knob-like 
posterior swelling in the female: 5 species. 

• See "Observations on the Natural History of the Oordlaess," by J. Lead?, 

Proc A. N. a.. Pblla.. Vol. 5, p. 282. "The Ad a It Organisation ot~ 

LeUr," by T. H. Montgomery, Zool. Jabrb., VoL 18, p. 887, 1BQS. 


0. morgani Montgomery (Fig. 364). Length 6 to 22 cm.; color 
brown; head white: eastern states. 


Marine worms with body faintly ringed externally 
and with 2 rows of fine bristles on each side; anus absent; 

tail of male curved ventrally and ends with 
a conical projection: 1 genus and species, 
which is found swimming at the Surface of ' 
the sea. 

Neotonexa Verrill. With the char- 
FigT364 acters of the family. 

mXif N. agile* Verr. (Fig. 365). Length of 

Wnd fem2fe d ° f male 5 to 20 cm.; of female 3 to 6 cm.; *Sfi^L 
(Montgomery). thickness 3 to X mm . color grayish-white: •"* (Ward) ' 

marine, and pelagic at Newport, R. I., and Woods Hole; Naples; the 
larval form parasitic in small crustaceans (Palcemonetes) . 


Elongated, parasitic worms which live as adults in the intestine of 
vertebrates, to the walls of which they attach themselves by means of a 
retractile proboscis armed with hook-like spines, and as larvae in the 
bodies of small invertebrates, especially crustaceans. 

The body of the adult may be divided into three regions, the proboscis, 
the neck, and the trunk. The proboscis is a more or less cylindrical struc- 
ture at the front end of the body provided with several rows of recurved 
spines. The neck is a continuation of the proboscis, but is without spines 
and is sharply set off from the trunk. The trunk forms the principal 
part of the body and is usually smooth, but may be annulated or spinose. 
T?he integument consists of a cuticula and a subcuticula; in the latter is a 
network of fibers and also large spaces of lacunae, and beneath it are 
circular and longitudinal muscle fibers. A large body cavity is present 
Extending backwards from the base of the proboscis in most forms is the 
proboscis sheath, a muscular sac into which the proboscis can be invagi- 
nated and thus retracted. In certain forms, however, the sheath is inserted 
near the middle or forward end of the proboscis, in which case it can be 
only partially retracted or not at all Extending backwards from the base 

* See "On Nectonema agile Verrill," by H. B. Ward, Bull. Mas. Comp. Z00L, VoL 
23, p. 135, 1892. 

t See "Geschichte and Ergebnisse der Ecblnorbynscben Foracbung," etc., by M. 
Ltihe, Zool. Annalen, Vol. 1, p. 139. "Acantbocepbalen," by M. Lflne, Sttuwauer- 
fauna Deutscblands, Heft 16, 1911. „ 


of the neck is a pair of long projections of the subcuticula called the 
lemnisci, the function of which is not known. The excretory system con- 
sists of a pair of nephridia which unite and open into the reproductive 
dnct. The nervous system consists of a central ganglion in the proboscis 
sheath and two main nerves which run backwards; no special sense organs 
are present No digestive tract is present. 

The Acantkocephala are unisexual. Extending back from the probos- 
cis sheath is a prominent band-like structure called the ligament which ends 
in the hinder part of the body cavity. In the male two ovoid testes are 
connected with the ligament, the vasa deferentia, with which several glands 
are joined, passing back to the complex genital opening at the hinder end 
of the body. In the female the ovary is also in the ligament; the ova 
escape into the body cavity whence they pass through an oviduct of com- 
plicated structure to the external opening at the hinder end of the body. 
Fertilization takes plaee in the body cavity and the embryonic development 
takes place there. The eggs then pass out and in order to develop farther 
must be swallowed by a crustacean or insect. The larval worm then bores 
through the intestinal wall of this intermediate host and encapsules itself 
in the body cavity, where it remains until the intermediate host is swal- 
lowed, probably usually in drinking water, by the final host, to the intes- 
tinal wall of which it fastens itself. The class contains 4 families, 12 
genera, and over 100 species. 


With the characters of the 
order: several genera. 

1. EcmxoHnKmm 0. F. 
Midler. Body smooth, although 
often wrinkled after death: nu- 
merous species. 

E. anguillaa Mull. (Fig. 
366). Body orange-colored, 6 to 
29 mm. long; proboscis with 8 or 
10 rows of hooka; neck long: in 
numerous fresh-water fish; com- 
mon; Europe; larva probably in 
Gammarun and small fishes. 

E. ranae Schranfc. Body 5 
to 60 mm. long; proboscis with 12 
to 20 rows of hooks: in frogs, toads, and salamanders; common; Europe 
larva in A»elliu. 

Fig. 86fU~-EcMnorhintaAi>« anguillat 
(SfliBW. F. Deut.). A, entire worm: 1. 
proboHC In ; 2, Icmilid; 3, probosciH 
- ' ' ' *" Hb; «. genital 




Body large, and annulated; lemnisci long and twisted: 1 genus. 
Gxgavtobktvchus Hamann. With the characters of the family: 
1 speeies. 

G. hirudinaceus (Pallas) (G. gigas Block) (Fig. 
367). Body white, tapering posteriorly, proboscis almost 
spherical and with 6 rows of 8 hooks each; male 6 to 9 
cm. long and 4 mm. thick ; female up to 50 cm. long and 
Fie. 367 4 to 9 mm. thick: in the intestine of pigs and often a 

CHgantorhynchu* ... ,. . 

giga* (Ward). common and dangerous parasite; the intermediate host a 
A. female 
B, male. beetle grub, which pigs often eat. 


Minute, aquatic animals which in structure bear a close relation to 
the trochophore larva of the annelid worms and mollusks. The body is 
unsegmented and often externally annulated or ringed and is never com- 
pletely ciliated, although in most of them groups of cilia occur in pertain 
regions. A spacious body cavity is present, which is not however .limited 
by a peritoneum. The Rolifera, by far the largest of the three classes/tire 
characterized by the ciliated disc-like front end of the body and usually 
also the forked organ of attachment at the hinder end. The other two 
classes comprise a few species of peculiar microscopic worms which are 
often included among the Rotifera, but which lack the anterior disc and 
differ from them also in other important respects. The subphylum con- 
tains 3 classes. 

Key to the classes of Trochelminthes : 

Ox External cilia present. 

5 t Anterior ciliated disc present 1. Rotifera 

5, Ventral surface only ciliated 2. Gastrotricha 

a. External cilia absent 3. Kinobhyncha 

Class 1. ROTIFERA.* 

Rotifers or wheel animalcules (Fig. 379). Microscopic, aquatic ani- 
mals, the body of which is composed of three divisions, the head, the trunk, 
and the foot. The head bears the corona, which is a ciliated disc forming 

* 8ee "The Rotifera or Wheel Animalcules," by C. T. Hudson and P. H. Gosse, 
1889. "The Rotifera of Sandusky Bay/' by D. 6. Kellicott, Proc. Am. Mlc. Soc, Vol. 
18, p. 155, 1896. "The Rotifera of Sandusky Bay/* by same. Ibid., Vol. 19, p. 43, 
1897. "Rotatoria of the United States," by H. S. Jennings, Bull. U. S. Fish. Com. 
for 1899, p. 67, 1900. "Synopsis of the Rotatoria/' by same, Am. Nat, Vol. 85, p. 
725. "Die Sttsswasserfauna Deutschlands," Heft 14, 1912. "Index of the Rota- 
toria/* by H. K. Harring, Bull. 81, U. 8. Nat Mus., 1918. 


the front end of the body and in the middle of which is tne mouth, and 
the special sense organs. The cilia are evenly distributed over the corona 
in the most primitive rotifers; in others the corona is variously lobed and 
the cilia are in groups and usually confined to the margin and the area 
just within the margin. These marginal cilia in numerous common rotifers 
whirl in opposite directions on the two sides of the corona and resemble 
revolving wheels, giving the group its name. The special sense organs, 
when present, consist of one to three eyes and one to four tentacles. The 
trunk is in many rotifers encased in a shell called the lorica which is the 
thickened cuticula; it is often provided with spines and other projections. 
The foot forms the hinder portion of the body : it is usually retractile and 
in most rotifers ends with one, two, or several toes. Glands are present 
in it which secrete an adhesive substance by means of which the animal 
can attach itself temporarily. 

The mouth opens into a large muscular pharynx called the mastaz 
in which are paired jaws or trophi, the working of which is a noticeable 
feature in rotifers. In some rotifers (Stephanops) the pharynx is thrust 
out of the mouth and used as a proboscis to take in food. A narrow 
OBSophagus joins the pharynx with the large stomach, which has a pair of 
large gastric glands and is joined with the dorsal anus by the short intes- 
tine. In some forms the intestine ends blindly, there being no anus. The 
nervous system consists of a brain dorsal to the pharynx and nerves ex- 
tending from it; a subcBsophageal ganglion is present in some forms. A 
pair of kidney tubules which contain fame cells open into a contractile 
bladder, the vacuole, which communicates with the hinder end of the intes- 
tine. The sexes are distinct The males are small and without digestive 
organs and usually much less numerous than the females ; in many species 
they have not been found at all. The female has usually a single small 
ovary and a large yolk gland which are joined with the cloaca by an ovi- 
duct, the lower end of which acts as a uterus and retains the young, in a 
large number of species, during development, so that they are born alive. 
The females reproduce parthenogenetically : at certain times, however, 
males are born and the fertilized eggs then produced are called "winter" 
or resting eggs and can resist cold and drought. Budding and fission do 
not occur. 

Hdbit8 and Distribution.— The majority of rotifers are solitary, free- 
living animals, although a few species are sessile, living in tubes com- 
posed of their own secretions or of foreign matters, and a few are colonial 
They are typically fresh-water animals and are everywhere abundant, but 
a few species are marine. They are also usually rather rigidly confined 
to certain environments, some living among plants and some being pelagic. 
Moat of the common species are cosmopolitan in their distribution. Some 


rotifers and their eggs can withstand desiccation many years when taken 
from the water and are often blown great distances by the wind or curried 
on the feet of birds. The food of most forms consists of minute plants 
and animals, but a few species are parasitic. 

History.— Rotifers have been known since the time of Leeuwenhoek, 
who discovered them in 1703. 0. F. Miiller in 1786 gave those known at 
his time binominal names, classifying them with the Infusoria, Ehren- 
berg, in his epoch-making work on Infusoria published in 1838, described 
great numbers of rotifers and laid the foundation of the present classifi- 
cation. Wiegmann in 1832 had, however, already removed them from the 
Infusoria and placed them among the worms. The monograph of Hudson 
and Gosse contains the modern classification of the group. 

About 850 species of Botifera are known, of which about 250 occur 
in this country. They are grouped in 3 orders. 

Key to the orders of Botifera: 

Ox Sessile or colonial and usually tubicolous (except Trochosphtera) . 

1. Bhizota 

a, Free-swimming; not tubicolous and non-colonial rotifers. 

ft. Rotifers which creep like a leech, but can also swim 2. Bdelloida 

b t Rotifers which do not creep but swim 3. Ploima 

Order 1. RHIZOTA. 

Usually sessile rotifers living in tubes composed of a transparent 
secretion or of fecal or other substances; some forms are colonial and a 
few are free-swimming: 3 families. 

Key to the families of Bhisota here described : 

a l Corona with prominent non-vibratile cilia usually on lobes ; vibratile cilia 

very small 1. Flosculariidae 

o, Corona without non-vibratile cilia; colonial or not 2. Mblicebtidab 


Solitary, sessile, or free-swimming rotifers living in a transparent 
tube; corona lobed in most cases and bearing groups of long, often non- 
vibratile cilia; vibratile cilia few, about the mouth: 3 genera. 

Key to the genera of Flosculariidae here described: 

Ox Lobes of corona knobbed or blunt, or absent 1. Flosculabia 

Os Lobes long and pointed 2. Stephanocbbosj 

1. FLOSOuXARiAf Oken. Body in a transparent tube; corona with 
3 to 5 lobes, or not lobed, and bearing long non-vibratile cilia; the young 
of all and the adults of certain species free-swimming: about 30 species, 

• See "On the Morphology of the Rotatoria n Family Flosculariidae/* by T. H. 
Montgomery, Jr., Proc. Acad. Nat. Sci., Phila., 1903, p. 363. 

t See "On Floscularla Conklinl Not. Spec, with a Key for the Identification of 
the Known Species of the Genus/' by T. H. Montgomery, Jr., Biol. Bull., Vol. 5, 
p. 233, 1903. 

S0T1FERA 233 

F. ornata Ehrenberg. Lobes 5, each with a round knob which bears 

the cilia; foot about twice as long aa the body; no eyes; length .5 

mm.: common and sessile; among water plants. 

F. campanulate Dobie (Fig. 368). 
Lobes 5, distinct and not knobbed ; cilia 
non-vibratile on entire margin of the 
bell-shaped corona; sessile; length .6 
mm.: often common. 

F. pelagic* Rousselet. Corona cir- 
cular, but slightly lobed with short, 
non-vibratile cilia; free-swimming. 

2. STirsJUTOCBBOB Ehrenberg. 

Lobes 5, very long, slender, and point- 

Fl*\ 868 eo J the cilia on them being non-vibra- Fig. 369 

J2Sm5*U tile and in rows or whorls; tube trans- H *SJ£Ei£ M 

(Montgomery). pftrent . ^ yery ^ j ^^ (ika Hosiery). 

8. flmhrlatns (Goldfuss) (S. eichhornii Ehr.) (Fig. 369). Length 
1.6 mm.: on aquatic plants; not common. 

Colonial or not; usually tubicolous; corona 2 or 4 lobe d with a 
continuous row of large marginal cilia; 1 to 3 antennae, 1 dorsal and 2 
ventral: 10 genera. 

Key to the genera of Melicertidae here described : 
(t, Non-colonial rotifers. 
b, Corona distinctly 2 or 4-lobed. 

c, Corona 4-lobed 1. Meucebta 

e. Corona 2-lobed. 2. Limnias 

b. Corona ova) or nearly circular and indistinctly 2-lobed. 
•, Colonic roHfm. «• *™" 

6, Colonies sessile, tubicolous or not 

o, Not tubicolous. 4. Megaxotbociia 

«, Animals in transparent tubes 5. Laciniti.abia 

b, Colonies free-swimming, pnltimla tubicolous . 6. Conochilus 

1. Mkuoehta Schrank. Corona large, with 4 large 

lobes; 3 antennae, 1 minute dorsal and 2 larger ventral uefiJcrta 

ones: 4 species. ,. ^og;' 

* (from SUmw. 

M. ringenB Schrank (Fig. 370). Tube formed of *■• DeuL). 
spherical pellets ; length .8 mm. : common on water plants. 

M. melicerta (Ehrenberg). Tube gelatinous; length 1 mm; ventral 
antennae very long: on water plants. 

2. LtmriAa Schrank. Corona broad, with 2 lobes; tube membra- 
nous, often roughened by dirt and sometimes simulated; antennae as in 
Melicerta : 3 species. 


L. ceratophylli Schrank (Fig. 371). Tube not annulated; length 
mm.; ventral antennae short: on water plants; abundant. 

L. annulatus Bailey. Tube annulated; body with 5 
horn-like dorsal processes ; length 1 mm. 

3. (EoilTEB Ehrenberg. Corona a wide oval; lobes 
indistinct; tube irregular or absent; dorsal antenna minute 
or absent : 10 species. 

0. crystallinua Ehr. Tube variable, transparent, often 
covered with dirt; ventral antennae small, wide apart; 
length A mm. 

0. mellcorta (Ehr.). Two long dorsal projections just 
below the corona, sometimes antler-like; tube formed of 
pellets and very short, or wanting: common. 
1. HsQALOTxOOKA Ehrenberg. Colonial and sessile, 
each colony appearing to the eye as a grayish ball; not 
tubicolous; corona broad, reniform; antennae inconspicu- 
ous: 2 species. 

M. alboflavicans" Ehr. (Fig. 372). Four opaque warts 
in a row just beneath the corona; length 2 mm., of colony 

conned ol 

6. Lacihularia Schweigger. Colonial and similar to %£JtoS!j2j 
Megalotrocha bnt each individual is in a transparent tube : 'Voent?"' 
1 species. 

L. socialis (Pallas). Length 2 mm., of colony 3 
mm.: on water plants; less common than above. 

6. Conoohtlus Ehrenberg. Free-swimming pelagic 
colonies, each individual in a transparent tube: 3 

0. TOlvox Ehr. Colony spherical, consisting of 10 
Fig 873 * :o ^" individuals arranged radially; ventral antennae 

€ ££to££" separate except at base; length .6 mm., of colony 1 

tf ""i>eul" w ' F ' mm - : common. 

0. unicornis Rousselet (Fig. 373). Colony irreg- 
ular, containing few individuals; a single large ventral antenna situated 
on the corona: common. 

Order 2. BDELLOIDA. 

Non-tubicolous rotifers (with a few exceptions) which swim with 

the corona and creep like a leech by attaching alternately the front and 

hind ends of the body; body cylindrical, with a cuticula composed of 

rings which can be telescoped; foot usually ending with 3 toes and with 



2 or 4 spurs a little way up; a dorsal proboscis behind the corona; 
ovaries 2: 2 families. 


Corona composed of 2 circular and separated retractile lobes, making 
2 distinct wheels; proboscis and tentacle present: 4 genera. 
Key to the genera of Philodinidae here described : 

Ox Two eyes present 

b t Eyes on the proboscis 1. Rotifer 

6, Eyes on neck, directly over the brain and the jaws 2. Philodina 

«, Eyes absent 3. Callidina 

1. Botifsk Schrank. Body long and slender and 
very retractile : among plants and dirt : 9 species. ». y^=^j i 

R. vulgaris Schrank (Fig. 374). Body whitish and ffi J=^{ % 
opaque, gradually tapering to the foot, which makes 
up half the animal ; spurs not twice as long as width of ^ 
body; length .5 mm.: common; also in salt water. 

B. tardigradus Ehrenberg. Body dark brown in 
color, long and slender; spurs 3 times as long as the RotyervuUfarU 
width of body where attached; length .8 mm.: common. ^"toJ^ntalaV" 

2. Pkilodzha Ehrenberg. Body rather thick, f usi- \ proboscis" 

form; 2 red eyes behind the pro- s,ten£icle. 

boscis; often in infusions: 6 species. 

P. aculeata Ehr. Dorsal surface of body beset with 

strong spines; length .5 mm.: common. 

■™ P. roseola Ehr. (Fig. 375). Body rather slender 

and often rose-colored; foot not distinctly set off; 
length .5 mm.: common. 

3. Gaxudiha Ehrenberg. Body elongate, without 
eyes, the jaws often with fine transverse ridges: many 
Fi*. 375 species. 

PW oESm 9eola °' ele * anfl Ehr - Each J aw with 10 ndges, cuticula 

SOssw. F. Dent), smooth; length .35 mm.: common in infusion. 

Order 3. PLOIMA. 

Non-tubieolous rotifers, which swim and do not creep like a leech, 

but may creep with the toes or may leap ; some are parasitic : 2 suborders. 

Key to the suborders of Ploima: 

Oi Without shell (lorica) 1. Illobioata 

a, With lorica 2. Lobioata 

Suborder 1. ILLORICATA. 

Ploimate rotifers with a flexible cuticula and no shell (lorica) : 6 


Key to the families of lUoricata here described : 
O) No foot present ; animals transparent, short and more or less spherical 

&i Animals spherical with a ring of cilia near equator 1. Tboohosf&bbzdai 

hi Body sac-shaped. 

4 No long lateral appendages 2. As planch win as 

c. Long lateral appendages present with which the animal jumps. 

3. Tbiabthbida* 
a, Foot with 2 toes present. 

h t Corona with 3 to 7 large prominences with setae 4. IIydatinidas 

0, Corona without these ; body elongate, often with a pair of ciliated pro- 
jections (auricles) 5. Notommatluab 


Spherical rotifers without corona or foot and with an encircling 
band of cilia near the equator or towards the forward pole; mouth 
ventral and anus at the hinder pole; the viscera are in the hinder hemi- 
sphere: 1 genus. 

Tkochospkx&a Semper. With the characters of the family : about 
3 species. 

T. aolfltitialis Thrope (Fig. 376). Band of cilia between equator 
and forward pole ; diameter 2 mm. : in the Illinois River and at Put-in-Bay, 
Lake Erie; Asia. 


Large transparent sac-shaped rotifers, without anus and usually 
pelagic: 3 genera. 

1. Asflamchma Gosse. Foot absent; jaws large; animals vivipa- 

Fig.378 Fig. 377 Pig. 378 

Fig. 378— Ttochotpttara toMtttalUi (Delate et Herouard). I, brain ; S, month; 
3, kidney tubule; 4, anus- 5, intestine ; 6, ovary- 7, dorsal nerve. Fig. 377 — 
Anplartchna haricii (from SUebw. F. Deut.l. Fig. 378— Polyarthra platypters {team 
Btissw. F. Deal.). 

rons, the embryo being frequently seen in the mother; 1 or 3 eyes present ; 
corona with two slight elevations: about 7 species. 

A. prlodonta Gosse. Body without humps and barrel-shaped; eyes 
3; length .5 mm.: often very common; pelagic. 

A. herricki* De Guerne (Fig. 377). Body amphora-shaped and 
without humps; eyes 3: pelagic. 

8. Jennings, Boll. 

2. ASFLAIOKxonri De Guerne. Foot present; animals viviparous: 
2 species. 

A. multkeps Schrank. Foot small; length 1 mm.: pelagic. 


Foot absent; long paired appendages at the side by means of which 
the animal skips or swims and which may give it the appearance of a 
crustacean: several genera. 

Poltaxthka Ehrenberg. Body rectangular with 12 long blade- 
ehaped appendages with serrate edges arranged in 
4 groups: 1 species. 

P. platyptera Ehr. (Fig. 378). One eye pres- 
ent; length .15 mm.: very common both at surface 
and bottom. 


Body cylindrical or sac-shaped with a short 
foot which has 2 small toes ; corona with a number 
of elevations bearing setae: 5 genera. 

1. Htdatxwa Bhrenberg. With- 
out eyes, but with a tentacle: 8 

Big. 81 

(lurn Stlaaw 

Fig. 379 

Btldailna tenia 

(SUbdw. F.Deut.). 

1, corona ; 2. month ; 

S, maatai ; 4, gaatrlc 

gland ; 5, stomach ; 6, 

ovary ; 7, yolk gland ; 

8, lateral sense organ ; 

9, Intestine; 10. kid- 
ney tubule : 11, vacu- 
Alai 12. an D a; 18, 

oda; 14, 

H. senta" Ehr. (Fig. 379). 
Body large, .5 mm. long, trans- 
parent: often common. 

2. NOXOM Hudson. Single eye 
present; corona large with a ring 
of cilia and bearing several large 
prominences crowned with setae: 
several species. 

N. brachlonus (Ehrenberg) 
(Fig. 380). Body large, quadran- 
gular and transparent; foot half as long as body and little retractile; 
length £ mm.: often common. 


Body soft and elongate; corona oblique in position, without lobes, 
and covered with cilia and often with a pair of lateral ciliated projec- 
tions called auricles: 15 genera. 

* Bee "Studies In tbe Ufa Cycle of Hydatlna leota," by A. F. Shall. Jour. Ex. 
ZooL, Tola. 8, 10, and 12. 1810-1912. "The Influence of Food In Controlling Sax ID 
Sydattna aentt," by D. D. Whitney, same, Vol. 17, 1914. 


Key to the genera of Notommatidae here described: 

0, Auricles present. 
6, Bod; not conspicuously annulated. 

C Vet? large rotifers with 3 or 5-lobed brain 1. Coptus 

o, Not large and brain not lobed 2. Notommata 

6, Body conspicuously annotated 3. TApnsocAitPA 

a, Auricles absent. 

b, Toes minute 4. Pboales 

o, Toe* conspicuous 5. FuacuuBU 

1. Oofiub Gosse. Large rotifers, slow- moving, usually enlarged 
behind the middle; brain 3-lobed; body projects backward from the foot, 
forming a tail; auricles present: 7 species; vegetable feeders. 

0. pachynrus Gosse (Fig. 381). Tail rounded and thick; auricles 
large; brain 3-lobed; foot 2-jointed; length .33 mm. 

Fig. 3S1 rig. 883 Fix- 388 

Fig. 8B1 — Copeue vachyurw (from Rta*. F. Dent). Pig. .182 — Sotommata Wpni 

(8Umw. F. Dent). Fig- 883 — Tavhrocampa annuloia (SUsew. F. Deut.). 

2. NoiomuTA Ehrenberg. Small rotifers with an elongate body 
and auricles; tail usually present; foot and toes usually small: many 
species; among water plants. 

N. tripns Ear. (Fig. 382). Tail ae long as the toes, the animal 
appearing to end behind in 3 toes; length .1 mm 

N. truncata Jennings. Body red in color, long and truncate at each 
end; cilia extending on to ventral surface; foot very smalL 

3. Taphbooakpa Gosse. Body small and with numerous perma- 

tnent simulations; small tail just above the foot: 4 species. 
T. annuloea Oosse (Fig. 383). Minute rotifer with a cyl- 
indrical body and with a pair of small auricles; length ,1 mm. 
4. Pro ales Oosse. No auricles or tail present; toes 
inconspicuous; body small and cylindrical: 8 species. 
P. aordida Gosse. Body thick; bead broad, with an eye; 
Fig 384 ^ oot Tery Droai *; toes conical; length .22 mm. 
'/orjSiio* *" Tu**JUU*lA Ehrenberg. Auricles absent; body cyl- 

Wtnti*' ii^n *! or bulging in the middle; toes conspicuous; eye red 
at apex of head : 12 species. 
F. fOrficok Ehr. (Fig. 384). Body cylindrical, with straight aides 
and .35 raw. long: abundant. 


Suborder 2. LORICATA. 

Lorica present, usually much flattened: 12 families. 

Key to the families of Loricata here described: 

Ox Foot absent 1. Anubjbidab 

o, Foot present. 
b t Foot transversely wrinkled or ringed (not jointed). 

C| Foot ending in a ciliated cup, without toes 2. Pterodinidab 

Of Foot ending in 2 toes 3. Brachionidab 

o, Foot not wrinkled or ringed, often jointed, with 1 or 2 toes, 
c, Toes not long and spine-like. 

&x Foot jointed ; lorica without dorsal spines 3. Bbachionidae 

dt Head with a chitinous covering like the visor of a cap ; foot and toes 

often very long ; 1 eye 4. Diwochartpab 

c, Foot usually very short and ending in 1 or 2 slender and usually long 
toes ; lorica usually flattened and ovate. 
tf, No arched shield over head. 

By Toes very slender and bristle-like, often very long 5. Rattultdab 

e% Toes 1 or 2 in number, slender and rod-shaped 6. Cathy pn id ah 

St Toes 2 in number, long and diverging 7. Euchlantdae 

df An arched shield over head 8. Colubxdae 

Family 1. ANTJRaSIDAE. 

Foot absent; lorica usually with 6 long spine-like projections at its 
anterior margin and 1 or 2 at its posterior : 3 genera. 

Aotbjba Ehrenberg. Lorica thick walled and opaque, 
marked with polygonal areas on its dorsal surface; empty 
loricas frequently found: 7 species. 

A. cochleaxis Gosse. Lorica prolonged posteriorly into 
a long spine, which, however, may be wanting; length 
J.6 mm. 

A. aculeate Ehr. (Fig. 385). Lorica quadrangular SJfJSJ 
with a spine at each of the postero-lateral angles; .15 mm. (somw'f. 
long. Deut5 ' 


Foot cylindrical and transversely wrinkled or annulated; body very 
retractile: 2 genera. 

Ptebobzva Ehrenberg. Lorica flattened; a pair of lateral semi- 
circles of cilia on the corona; 2 eyes; foot ending in a ciliated cup: 3 

P. patina Ehr. (Fig. 386). Lorica very transparent, flat and cir- 
cular and JL7 mm. long, without teeth: common among algae. 


Foot long, cylindrical, and usually not jointed, but annulated or 
wrinkled, with 2 toes; lorica squarish and flattened and usually with 
spine-like projections from its anterior margin: 3 genera. 


1. BBAOHXOHVS Pallas. Lorica arched dorsally, flattened veutrally; 
1 red eye: numerous species, some marine. 

B. rnbens Ehrenberg (Fig. 387). Six straight spines on anterior 
margin; no posterior spines; color pinkish: often common. 

B. bakari 0. F. Muller. Six spines on anterior margin, the 2 
middle ones carving outward; 2 lateral spines on posterior margin may 
be long, short, or absent; length 35 mm.: often very common. 

Fix. 386 — rtero Una patina (SQttw. F. Dent.). 
F. Deut). Fig. 388— Note** flwHfr 

B. militaris Ehr. Foot jointed; lorica with 10 anterior and 4. pos- 
terior spines, its surface facetted and covered with raised points; 
length 25 mm. 

2. Noteub Ehrenberg. Foot jointed; lorica oval and with 2 ante- 
rior and 2 posterior spines ; no eye : 1 species. 

N. qnadricornia Ehr. (Fig. 388). Dorsal surface facetted, whole 
surface roughened; length .35 mm, 


Lorica more or less cylindrical and usually with an 
anterior dorsal projection over the head; foot very long 
with 2 long toes: 4 genera. 

1. Ehrenberg. Lorica vase-shaped, smooth, 
and transparent, without the dorsal projection; 1 eye; 
foot and toes very long: several species. 

S. longicaudom (0. F. Muller) (Fig. 389). Body 

cylindrical; toes and foot longer than the rest of the 

body; .4 nun. long. 

ecoHdiwm 2. Stephanopa Ehrenberg. Head covered with a large 

lonpicanaum ... „ 

(SflMw. f. semicircular shield; foot and toes not usually long; 1 to 3 

long movable spines project from the back : several species. 
S. longisplnatui Tatem. One long spine from the middle of back; 
length 15 mm. 


Family 5. BATTULIDAE.* 

The very short foot ends in one or more slender, often very long, 
bristle-like toes; lorica more or less cylindrical; 1 eye: 2 genera and 
35 species. 

1. Kattuxus Lamarck. One long toe, often as long as 
the rest of the body; a short toe also usually present which 
is not a third the length of the long toe : 20 species. 

B. longiseta (Schrank) (R. bicornis Ehrenberg) (Fig. 
390). Two spines of unequal length at the anterior margin 
of the lorica; toe two-thirds the length of the body; length 
.5 mm.: common. «. 3fi0 

B. mucosas Stokes. Lorica with 2 parallel ridges close fSE$Sl* 
together for half its length; body ovoid: length 2 mm.: often < De£t) F ' 

2. DlTOELLA Bory de St. Vincent. Two toes present of equal 
length or one more than a third the length of the other: 
14 species. 

D. tigris (0. F. Miiller) (Fig. 391). Toes equal and 
long; body cylindrical, 2 mm. long with a tooth on 
anterior margin of the lorica: very common in aquatic 
vegetation in quiet water. 

D. porcellus (Gosse). Toes slightly unequal, folded 
under the body, which is short, curved, and .15 mm. loner; 

Diurella tigris 

(Jennings). lorica with 2 marginal teeth: very common. 


Body broad; dorsal plate convex, ventral plate flat, the 2 plates sep- 
arated by a deep groove on each side; foot very short with 1 or 2 rod- 
shaped toes; 1 eye: 3 genera. 

1. Oathtpva Oosse. Lorica oval or nearly 
circular; 2 toes: 3 species. 

0. nngnlata Gosse. Body large, being .3 mm. 
long, including toes ; dorsal plate projecting over the _. 392 

foot; toes half as long as lorica: often very common. (Si thvi v a DB n iL > 

0. lnna (0. F. Miiller) (Fig. 392). Toes two- 
fifths as long as lorica; each with a distinct shoulder at side near the 
tip; length 2 mm.: often common. 

2. MOV08TYLA Ehrenberg. Body oval or nearly circular, with 1 
rod-like toe: 10 species. 

• 8ee "The Rotatoria of the United States, II ; a Monograph of the Battulldae," 
by H. 8. Jennings, Bull. U, 8, Fish, Com., Vol, 22, p. 273, 1903. 


M. bulla Gosse (Fig. 393). Dorsal plate very high; ventral plate 
somewhat convex; anterior margin with a notch; .25 mm. long: very 
i among aquatic plants. 

Family 7. EUCHJ.ANIDAE. 

Large transparent rotifers with a convex dorsal and 
a flat or slightly convex ventral plate; foot jointed, with 
2 large, diverging, blade-shaped toes : 2 genera. 

Etjohxamib Ehrenberg. Lorica oval and flat; eye 
present: 7 species. 

E. dilatala Ehr. (Fig. 394). Lorica with a pair 
of lateral flanges projecting from its ventral plate; 
anterior dorsal margin with a broad gap having a 
jr, 303 straight bottom; length 3 mm.: often very common in 

M °ff££iSg) lUl "I™*" vegetation. 

Head surmounted by an arched shield, appearing in a side view like 
a hook: 5 genera. 

1. Metopidia Ehrenberg. Lorica flattened, usually turtle-like in 
appearance; usually 2 eyes: 11 species. 

M. lepadelU Ehr. (Fig. 396). Lorica oval, without teeth or spines 

tig. SO*—EuchlatHi dilatata (SOuw, P. Dent). 
(SQmw. F. Dent.). Fig- 396— Monuro coin 

or prominent angles; 2 eyes; ventral plate indented behind; length .08 
mm. : often abundant among aquatic plants. 

M. acuminata Ehr. Lorica oval, ending behind in a sharp point; 
length .08 mm.: often common among aquatic plants. 

S. Moxt/Ka Ehrenberg. Lorica arched, more or less compressed lat- 
erally, often open mid- vent rally. 

M. colnrns Ehr. (Fig. 396). Length .1 nun.: often common among 
algae in the sea. 



Minute worms less than .5 mm. long with an elongated body, usually 
forked behind, with la ciliated ventral surface and a dorsal surface either 
bare or covered with bristles or scales arranged in longitudinal rows; 
head end contains the mouth and usually bears a pair of eyes and 
paired sensory bristles; digestive tract a straight tube with a long mus- 
cular oesophagus, extending to the anus, which is in the dorsal surface at 
the hinder end of the body; a pair of long kidney tubules opens into the 
intestine; a very large brain is present, dorsal to the oesophagus, from 
which nerves radiate; animals hermaphroditic, paired ovaries and testes 
being present in the hinder part of the body cavity; no genital ducts are 
present and it is not known how the very large eggs reach the outside; 
development direct: fresh-water animals found among infusorians and 
rotifers; about 32 species, of which 12 have been found in this country. 


With the characters given above: several genera. 

Key to the genera of Chatonotidae here described: 

Oj Posterior end forked. 
&t Back covered with spines or scales. 

<\ Caudal forks short 1. Chjetdrotus 

€, Caudal forks very long and segmented 2. Lepidodebxa 

h t Back not covered with spines or scales 3. Ichthtdium 

o, Posterior end not forked 4. Dasydytes 

1. Ckjbtoyotub Ehrenberg.f Gastrotricha with a short, unsegmented 

forked tail and with dorsal spines or scales; ^^ 

head formed of 3 lobes, usually with 2 pairs J W^R»vnS TjflT 

of tufts of sensory bristles and in some species 

... • • A i .j Fig. 307 — OhaUmoUu 

with a pair of eyes; ventral side larus (Stokes), a, dorsal 
a 00 aspect ; B, head, 

flat: 23 species. 

|fe[ 0. larus (0. F. Miiller) (Fig. 397). Back covered with 

short conical spines, the posterior ones being usually the 

larger; length .12 mm.: common. 

0. longispinosus Stokes (Fig. 308). Back with 2 

Fig. 398 transverse rows of long spines: often common. 

longispinosus 2. LEFZD0DEBXA Zeller. Back covered with scales; 

tail forks long and segmented: several species. 

L. rhomboides (Stokes) (Fig. 399). Forks of tail one-fourth the 

length of the body and composed of 20 segments; a deep, transverse 

depression back of the mouth ; length .3 mm. 

• See "BeltrXge snr Systematic der Gastrotrlchen," by T. GHlngpan, Zool. Jabrb. 
8yst, Vol. 26, 1908. "Die Sttsswasserfauna Deutschlands," Heft 14, 1912. 
t See "Aquatic Microscopy," etc, by A. C. Stokes, p. 185, 1896. 


3. Iohthydiuk Ehrenberg. Like Chtetonotus except that the back 
is bare: several species. 

L pcdura (0. F. Mtiller) (Fig. 400). A pair of vertical spines on 
the neck, and another pair near the hinder end; length .07 nun.: common. 

Fi K . 390— Ltptdoderma rhomboids* (BOsbw. F. Dent.). A, head: B. till ; C, dor**] 

scales. Fig. *0O— Ichlhydium podura (SDasw. F. Deut). 

Fig. 401— Daat/dytfg taltitan* (Stokes). 

4. Dabtsttxb Crosse. Body wide, with a distinct neck and head and 
no forked tail: several species. 

D. aaltitaJU Stokes (Fig. 401). Head with long cilia on both sides; 
neck very flexible; 2 sets of long bristles cross each other on the back; 
length .08 mm.: not common. 


Minute marine worms less than .5 nun. in length; 
body arched dorsally and concave ventrally, and composed 
of a series of rings; body cavity not segmented; outer sur- 
face not ciliated but provided with spines and bristles ; head 
and neck retractile, with a ring of hooks around the 
month and a number of long locomotory spines; hinder 
end usually forked; paired genital pores and paired 
excretory pores near hinder end; sexes separate: about 30 
Fig. 402 

(from Clans). 

With the characters given above: 2 genera. 

Eohihodebzs Dujardin. Eyes present: several species in the 
Mediterranean and Atlantic. 

E. dnjardiii Claparede (Fig. 402). Body composed of 13 rings; 2 
red eyes; color reddish: in mad and on algae. 


Subphtlum 4. BBYOZOA.* (Polyzoa.) 

Minute and mostly colonial animals which are attached to rocks, 
plants, and other objects in the sea or fresh water. The colony is usu- 
ally made up of hundreds or thousands of individuals which have arisen 
from one another by a process of budding, and is often mosslike in 
appearance, whence the name of the group. The Loxosomidae are the only 
non-colonial family. The individual members of a colony are called the 
zooids: they are more or less cylindrical in form and are aften polymorphic 
in structure. The outer wall of the zooid is in most cases a thick cuticula 
secreted by a hypodermal cell layer: it is often hardened by the presence 
of calcium carbonate and forms a rigid case within which lie the soft parts 
of the animal. This case, which is called the ectocyst or zocecium (Fig. 
406,8), will often remain long after the death of the animal and the dis- 
appearance of the soft part. In Pectinatella and some other forms the 
body wall is fleshy or jelly-like. 

The soft parts of a zooid consist of the viscera and the tentacle- 
sheath with the tentacles which constitute the anterior end of the body. 
The tentacles are hollow and ciliated and are borne upon a prominent oval 
or horseshoe-shaped ridge called the lophophore (Fig. 406,1). 

The body wall below the tentacles is highly flexible and in the 
Ectoprocta these can be completely retracted within the zooocium. In the 
center of the lophophore is the mouth and in the Entoprocta the anus 
also: in the Ectoprocta the anus is situated just outside of it. The ten- 
tacles are the only portion of the external surface of the Bryozoa that 
is ciliated. 

The internal organs differ very much in the two great groups of the 
Bryozoa and will be described when these are presented. 

Distribution and Habits.— -The majority of Bryozoa are marine, being 
found from tide water to very great depths. Between tide lines and in 
shallow water incrusting and creeping colonies which are attached to rocks, 
shells, or seaweed are common, while in deeper water erect and branching 
colonies are the more abundant. No Bryozoa are parasitic, although many 
species live commensally with other animals or with plants. The group is a 
very ancient one, occurring in the Cambrian and all subsequent formations. 

• See "Report upon the Invertebrate Animals of Vineyard Sound/' etc., by A. B. 
Verrill, Rep. U. 8. Com. Fish., 1871-72, p. 292. "British Marine Polyzoa/' by 
Thomas Hlncks, London, 1880. "Synopsis of North American Invertebrates, I. 
Freshwater Bryozoa," by C. B. Davenport, Am. Nat., Vol. 33, p. 593, 1899. "Sponges 
and Bryozoa of Sandusky Bay," by F. A. Landacre, The Ohio Naturalist, Vol. 1, p. 
96, 1901. "The Bryozoa. Papers from the Harrlman Alaska Expedition," by Alice 
Robertson, Proc. Wash. Acad., Vol. 2, p. 315, 1900. "The Freshwater Bryozoa of 
the United States," by C. B. Davenport, Proc. U. S. Nat Hus., Vol. 27, p. 211, 1904. 
"The Bryozoa of the Woods Hole Region," by R. C. Oaburn, Bull. Bur. Fish., Vol. 30, 
1012. "The Bryozoa of Tortugas," by same, Pub. No. 182, Cam. Inst, Wash., 1914. 


History.— The Bryozoa were thought to be seaweeds by the earlier 
naturalists. LinnaBus grouped them with the corals and hydroids. Here 
they remained until 1830, when J. V. Thompson separated them from the 
polyps because they possess a digestive tube and called them Polyzoa, by 
which name they are still known by English and many American zoolo- 
gists. In 1831 Ehrenberg performed the same service and called the new 
group Bryozoa, which is the name in use among continental and many 
American zoologists. In 1841 Milne-Edwards created the phylum Mollus- 
coidea to include the Bryozoa and Tunicata, in which the first named group 
will still be found in many textbooks. The terms Ectoprocta and Ento* 
procta were introduced by H. Nitzsche in 1870. 

About 1,700 species of marine and 35 species of fresh-water Bryozoa 
are known, which are grouped in 2 classes. 

Key to the classes of Bryozoa: 

Ox Tentacles not retractile into the zooecium 1. Entopbocta 

a, Tentacles retractile 2. Ectopboota 

Class 1. ENTOPBOCTA.* 

Minute, primitive Bryozoa, in which the anus is within the circle of the 
lophophore. The body consists of a calyx or head and a contractile 
stalk, the former containing the viscera. The lophophore is circular 
and supports a single row of tentacles. The depression within the 
lophophore, which is called the vestibule, contains the mouth and the 
anus (Fig. 405) ; projecting over the former is a lip called the epistome. 
The lophophore cannot be retracted into the zocBcium, but the tentacles 
can be rolled into the vestibule and partly covered by an integumental 
fold which arises at their base. 

The viscera fill almost the entire space within the body. What 
space is left and the entire inner portion of the stem are occupied by a 
gelatinous parenchyma, so that a definite body cavity is wanting. The 
digestive tube is U-shaped, an oesophagus, stomach, and intestine being 
distinguishable. The genital organs consist of a pair of gonads which 
open into the vestibule. The animals are either unisexual or hermaphro- 
ditic : in Loxosoma davenporti the gonads function as ovaries first and as 
testes later. A pair of kidney tubules with flame cells open either into 
the vestibule or the rectum. The nervous system consists of a central 
ganglion situated between the mouth and the anus and radiating nerves. 

The Entoprocta are found in both salt fend fresh water. They are a 
small group comprising about 20 species, which are grouped in 3 families. 

• See "Studies In Pacific Coast Entoprocta," by A. Robertson, Proc. Cal. Acad. 
Set, Vol. 2, p. 320, 1900. 


Key to the families of Entoprocta: 

Ox Solitary Entoprocta 1. Loxosoiodah 

a, Colonial Entoprocta. 

hi Freeh-water Entoprocta 2. Ubnatellidak 

ft, Marine Entoprocta 3. Psdicellhodae 

Fig. 403 

Loctosoma davenporti 


1, lophophore ; 2, rectum ; 

3, bod. 



Solitary Entoprocta, which, however, often 
bear young buds, with 10 to 26 tentacles, with 
a contractile stalk at the base of which is a 
foot gland which is of use in attaching the 
animal and may be wanting in the adult 
animal, and with an obliquely placed lopho- 
phore: 3 genera. 

Loxosoma Keferstein. With the char- 
acters of the family: 15 species, which are 
usually associated with marine annelids. 

L davenporti* Nickerson (Fig. 403 ) . Length 
up to 2.4 mm.; small foot gland present; tenta- 
cles numbering from 22 to 26 ; from 
2 to 12 buds usually present; anus 
elevated on a cone; mammary 
organ present in the floor of the 

vestibule to which developing embryos attach themselves to 

get nourishment: abundant in Vineyard Sound. 
L. minuta Osburn. Body oval, .3 mm. 

long: on Phascolosoma and Phascolion on 

New England coast. 


Colonial, fresh-water Entoprocta, each 
colony consisting of a few zooids, which 
rise from a common disc; stalks long and 
jointed and branching: 1 genus. 

Ubhatella Leidy. With the char- 
acters of the family: 1 species. 

XJ. gracilis f Leidy (Fig. 404). Stalk up to 4 mm. long; calyx about 
a tenth as long and bell-shaped; usually 2 zooids in a colony: on the 
under side of stones in running water, in the eastern and central states. 

• See "Loxosoma davenporti," by W. S, Nickerson, Jour. Morph., Vol. 17, 
p. 351, 1901. 

t See "On Urnatella gracilis," by C. B. Davenport, Boll. Mus. Comp. ZooL, VoL 

Fig. 404 
Urnatella araciU* : 
three individuals 


Colonial marine Entoprocta in which the zooida rise from a creeping, 
branching stolon; the stalk is long and separated from 
the calyx by a diaphragm: 2 genera. 

PXDIOELLIXA Sara. With the characters of the fam- 
ily: 6 species, 3 in Long Island Sound. 

P. cernna (Pallas) (P. nutans Dalyell; P. americana 

" Leidy) (Fig. 405). Calyx cup-shaped with 12 to 24 

Padictliina tentacles; atalk yellowish-red in color, with or without 

(altered from spines on stalk and calyx and tapering towards the top: 
OtburD > . 
i, mouth on shells and algae in shallow water; Atlantic coast, from 

3, stomach. Labrador to Florida; Europe; often common. 


Bryozoa living in large colonies, in which the anus is outside the 
tophophore and tbis structure with the tentacles can be retracted into 
the zocecinm (Fig. 406). The body cav- 
ity is an extensive space which is lined 
throughout by a peritoneum consisting 
either of a single layer of cells or thin 
layers of an irregular cellular parenchy- 
ma. In certain species the body cavities 
of the zooids communicate with one an- 
other. The digestive tract is a wide 
ciliated U-shaped tube, the aboral por- 
tion of which is the sac-shaped stomach. 
Joining the aboral end of the latter or- 
gan with the base of the body cavity is 
a mesenterial strand called the funiculus. 
The animals are hermaphroditic, the 
gonads developing in the peritoneum, the 

testes usually on the funiculus and the "«• **»« — (c5fS2SJ5iSS.J>* * ctoproct 
ovaries on the lateral walls. The ova and „ t A e - n £ d "£? m $ SJS» : £ h" 
sperm, except in the fresh-water species, reu«rd). 1, lophophore; 2 month: 

* r r ' 3, idub ; 4. operculum : S, retrac- 

fall into the body cavity, where fertili- tile muscle; 8, funiculi; 7, di- 

J " festive tract ; 8, «oojdum. 

zation takes place. The eggs develop 

in the body cavity up to the larval stage in certain species, when 
the young animals reach the outside either through a birth opening 
or as the result of the disintegration of the parent. In other forms the 
fertilized eggs pass into special outgrowths of the body wall called rxeeia 
or ovicells (Fig. 414,1) and develop there. In the Phylactolaxnata the 


embryo develops in the ovary, receiving nutriment directly from the 
body cavity. 

All ectoprocts develop also asexually by budding, and thus produce 
the branching and incrusting colonies which characterize the group. In 
many species polymorphic zooids appear which differ much from the 
others in structure and perform certain specialized functions. These are 
the ooBcia, which are brood chambers, above mentioned, the avicularia 
(Fig. 411, A), birdhead-like structures which seize small animals in 
their jaws, and are probably defensive in function but also function in 
keeping the surface of the colony clean, and the vibracula (Fig. 411, B), 
whip-like appendages which wave about in the water and are also defen- 
sive. In the fresh-water Phylactolamata disc-like buds called statoblasts, 
which have a hard chitinous shell, develop on the funiculus and either 
float or drop to the bottom on the death of the animal in the fall of the 
year or in periods of drought. In the spring or on the return of the wet 
season each statoblast gives rise to a young colony. 

The Ectoprocta have great powers of regeneration. Periodically in 
the marine species the soft parts of the animal, with the exception of the 
body wall, break down and form a single round mass called the brown 
body. Later new organs develop, the brown body apparently being 
expelled from the body as waste matter. 

Kidneys have not been certainly demonstrated in Ectoprocta. No 
blood vessels are present, but a blood fluid fills the body cavity. The 
nervous system consists of a ganglion between the mouth and anus and 
nerves radiating from it: in many species no nervous system has yet 
been seen. No special sense organs are found. The class contains 2 
orders and the great majority of all Bryozoa. 

Key to the orders of Ectoprocta: 

Oi Mostly marine Ectoprocta, with a circular lophophore. . . .1. Gyhnolsmata 
o, Fresh-water Ectoprocta with a horseshoe-shaped or oval lophophore. 

2. Phylactoljemata 


Lophophore circular; mouth can usually be closed by a flap called 
the operculum; vibracula, avicularia, and ooecia often present: marine 
Bryozoa (excepting the Paludicellidae) including about 1,700 species, 
which are grouped in 3 suborders. 

Key to the suborders of GymnoUemata: 

a 1 Opening of sooecium wide and circular and not capable of being closed 

by an operculum 1. Cyclostoicata 

a, Opening of sooecium, when lophophore is retracted, more or less flattened 
and capable of being closed by an operculum. 

h x Operculum a movable horn-like valve 2. Chilostomata 

6, Operculum composed of a fringe of setae 3. Ctenostomata 



Suborder 1. CYCLOSTOMATA. 

ZooBcia tubular, in most cases densely calcareous, with a wide ter- 
minal, circular opening, and without operculum, avicularia, or vibracula : 
4 families. 

Key to the families of Cyclostomata here described: 

Ax Colony distinctly jointed, and erect 1. Cbishdab 

a, Colony not distinctly jointed, and either recumbent or erect. 

&! Colony usually branching and recumbent, or more or less erect (discoid 

in Diottopora) 2. Tubulifobidae 

6, Colony discoid 3. Lichenopobida* 

Family 1. CBISIIDAE. 

Colony erect and branching, calcareous and with horn-like joints so 
that it is more or less flexible, with jointed and often branching root 
fibers given off from the base or from the internodes which serve to 

fasten it; zooBcia in 1 or 2 rows; ten- 
tacles 8 in number; large ocecia pres- 
ent: 1 genus. 

Ceisia Lamouroux. With the 

Fig. 407— CrUiaeburneo (Osbnrn). characters of the family: about 35 

0, eburnea (L.) (Fig. 407). Colony white in color, forming bushy 
tufts from 8 to 25 mm. high; zooecia in 2 rows and alternate, slightly 
curved out, almost entirely adnate: cosmopolitan; common from Long 
Island Sound to Arctic Ocean; California; 
Europe; from low-water mark to 80 fathoms. 


Colony entirely creeping and incrusted or 
more or less erect, either simple or branched and 
often radiating from a central point; zooecia in 
1 or several rows, adhering to one another lat- 
erally, with the upper end more or less free: 
about 5 genera. 

Tttbttlxfoba Lamarck. Colony entirely re- 
cumbent or partially erect, forming a variously 
shaped expansion, either simple or branched; 
zooids tubular, arranged in divergent series: 
about 29 species. 

T. flabellaris (Fabricius) (Fig. 408). Colony 12 mm. in diameter, of 
a pale purplish color, flabellate when young, but more or less circular and 
lobed when old; zooecia punctate, long, and slender, .15 mm. in diame- 


Tubulipora flabellarU 



ter, crowded together and radiating from the center to the edge, and 
with the outer ends erect: Long Island Sound to Greenland, on algae, 
etc., in shallow water; Europe. 

T. fimbria Lamarck. Colony 12 mm. in size; fan-shaped and lobed; 
zocBcia slender, not raised at the outer ends, and wrinkled transversely: 
in shallow and deep water; North Atlantic; Europe. 

T. liliacea (Pallas) (T. pruinosa Stimpson). Colony about 9 mm. 
high and white, or often purple and punctate; branches in same plane: 
Atlantic coast; Europe; on shells, hydroids, etc. 


Colony discoid, flat, or more or less raised, forming either a simple 
disc or several confluent ones; zooBcia partially erect, forming distinct 
rows which radiate from a large central free area and are not close 
together, the spaces between being porous: 2 genera. 

Lichzvofo&a Def ranee (Discoporella Gray). Colony thin and lami- 
nate, sometimes composite: about 30 species. 

L. hispida Fleming. Single disc up to 6 mm. in diameter; each indi- 
vidual with 10 short tentacles: North Atlantic, on shells, algae, etc., from 
moderate to great depths; often common; Europe. 

L. verrucaria (Fabricius). Disc 3 mm. in diameter; zooecium with 
a rib : North Atlantic, south to Long Island Sound ; common ; Europe. 

Suborder 2. CHILOSTOMATA.* 

Colonies either erect or recumbent; zooids tubular, oval, or rectan- 
gular, and calcareous, horn-like, or membranous, the opening usually not 
terminal and usually closed by a movable operculum (Fig. 406) ; avicu- 
laria, vibracula, and ocecia usually present: about 36 families, all being 
marine, including the majority of Bryosoa. 

Key to the families of Chilostomata here described : 

Oi Colony not incrusting or foliaceous but usually dendritic. 
ft x Colony composed of a creeping base and erect shoots ; no avicularia or 

c x Zooids rising separately from the base 1. iETEiDAB 

c, Erect shoots composed of many zooids each 2. Eucratkidae 

ft, Colony dendritic, without a creeping base. 
c x Avicularia sessile and fixed. 
&x Colony slender. 

4 Branches flattened... 3. Cellulariidae 

e t Branches cylindrical 5. Cellariidae 

d, Colony foliaceous 6. Flustridae 

c, Avicularia pedunculate and jointed 4. Bioellariidab 

* See "Non-in crusting Chllostomatous Bryosoa of the West Coast," by Alice 
Robertson, Univ. of Cal. Pub., Vol. 2, p. 235, 1905. "The Incrusting," etc., by same, 
ditto, VoL 4, p. 253, 1908. "The Chllostomatous Bryosoa/' by G. M. B. Levlnson, 1909. 


a, Colony incrusting or foliaceous and strongly calcified. 
6j Colony incrusting ; front wall more or less membranous. 

d No ridges on front wall 7. Membraniporidae 

<*, Front wall with prominent transverse or radiating ridges. 

8. CaiBHiLiira>AE 

b t Front wall not membranous ; colony either incrusting or erect. 

d With a pore beneath the orifice 9. Miobopohellidae 

c, With no such pore. 
a\ Zooecia not perpendicular to general plane of colony and usually 

4 Opening of zocecium with an indentation in lower lip. .10. Mtbiozoidab 

e, No such indentation 11. Bschabidak 

d\ Zooecia vertical and heaped irregularly together 12. Celleporidak 

Family 1. ^TEIDAE. 

Zooecia tubular and erect, rising separately from a creeping stolonie 
stem with a terminal opening and a lateral membranous area at the 

upper end; operculum subterminal; no avicularia 
or vibracula: 1 genus. 

JEtea Lamouroux. With the characters of 
the family: 9 species. 

A. anguina (L.) (Fig. 409). Zooecia about 1 
mm. high, white and glossy, more or less bent, 
with a spa tula te upper end and a ringed stalk; 
stolon with regularly occurring thickenings, each 
of which is part of a zooecium: Long Island 
L&'Y<S3'vi7Sw Sound northwards from shallow to deep water on 

hydroids and seaweed; often common; Pacific 

Fig* 409 
JEtea anguina (Osborn). coast, cosmopolitan. 


Colony erect and branching; the zooecia narrowest at the base and 
expanding upwards, being linked together in a single row, or in double 
rows placed back to back; openings usually oblique; 
no avicularia, vibracula, or opercular 5 genera. 

1. Etto&atea Lamouroux. Colony composed of a 
creeping stolon and erect branching shoots; zooacia in 
a single row placed end to end; opening large and oval; 
ooecia terminal ; tentacular sheath terminating above in _ 410 

a ring of setae : about 4 species. Bucr %Sb nf?*** 

L. chelata (L.) (Fig. 410). Colony often much 
branched, occasionally not erect; branches spring from just below the 
opening: Vineyard Sound northwards, on seaweed, stones, etc., in shal- 
low water and between tide lines; often common; Pacific coast; 



2. Gbmellawa Savigny. Colony erect, branching; zocecia joined 
back to back, the pairs rising from the top of one another; aperture 
large: several species. 

G. loricate (L.). Colony bushy, up to 20 cm. high, brown in color, 
composed of long, straight branches; zoo&cia narrowed below; aperture 
oval: in northern seas; Vineyard Sound northwards; Alaska; Europe. 


Colonies erect, dichotomously branched ; zocecia in 2 or more rows in 

the same plane; avicularia and vibracula (Fig. 411), or the former alone, 

almost always present; opening not terminal, 

usually armed with spines and usually with 

an operculum: 8 genera. 

1. Menipka Lamourouz. Colony jointed, 

zooecia oblong, widest above, attenuated down- 
ward, usually with sessile avicularia and 

ocBcia; no vibracula: about 20 species, 7 

American, mostly on the Pacific coast. 

M. ternate (Ellis and Solander). Colony 

in small tufts, 25 mm. high; zooecia in 2 rows, 

alternate and arranged in groups of 3; long 

fibers extend from the zooBcia: circumpolar; 

Cape Cod northwards from shallow to deep water, on 
hydroids and shells ; Europe ; Pacific coast. 

2. Oabsksa Lamouroux. Colony not jointed; 
zocecia in 2 or more rows, quadrangular or ovate, with 
a very large opening; sessile avicularia and enormous 
vibracula as well as long, clasping fibers present : about 
15 species, 1 American. 
0. ellisi (Fleming) (Fig. 412). Colony with numerous branches, 25 

mm. high; zocecia in 2 to 4 rows and quadrangular; vibracula very long 

and serrate: circumpolar; Vineyard Sound northwards, from shallow to 

deep water; often common; Europe; Alaska. 

Fig. 411 

A. an avicularlnm 

B, a vibraculum 

(Delage et Herouard). 

1, nerve ; 2, muscles. 

Fig. 412 

Caberea ellisi 



Colony erect and branching; zooacia obliquely placed in 2 or more 
rows and conical or rectangular; stalked avicularia usually present and 
no vibracula; ocecia at the upper end of the zooecia: 16 genera. 

1. BiOBLUULlA Blainville. ZooBcia cornucopia-shaped, loosely joined 
together and directed obliquely sideways: about 15 species. 


B. ciliata (L.) (Fig. 413). Colony forming feathery tufts 12 mm. 
high, white in color; zocecium with 4 to 7 very long slender spines along 
its upper margin: Atlantic coast, on hydroids and algae; Europe. 

2. BircroLA Oken. Zooecia more or less quadrangular, 
arranged in 2 or more rows; opening large, not oblique; 
avicularia in form of a bird's head: about 35 species, 9 
on the Atlantic coast, 8 on the Pacific. 

Key to the species of Bugula here described: 

Ox Zooecia in 2 rows B. tubrita 

jHo*iiort *■ Zooecia in 3 or more rows. 

ciliata &i Avicularia not at base of aperture B. flabellata 

(Otburn). ft f Avicularia at base of aperture .B. mubrayana 

B. turrita (Desor). Colony up to 30 cm. or more in height, com- 
posed of fiat branches growing in spirals, each branch with 2 rows of 
zooBcia, each zocecium with a spine on the outer upper angle; color yellow: 
North Carolina to Casco Bay, very common in shallow water. 

B. flabellate (Thompson) (Fig. 414). Colony up to 25 
mm. high, composed of broad flat branches, each with from •• 
3 to 7 rows of zooecia, each upper angle with 2 spines; of 
an ashy color when dried, flesh color when alive: Vineyard 
Sound and northwards in shallow water; common; Pacific * 
coast; cosmopolitan. 

B. murrayana (Johnston). Colony a bushy tuft up Bwlfct 
to 50 mm. high and like the above, with 3 to 12 rows of ftjg 1 &£• 
zooecia; each upper angle with a stout erect spine and 2 lyf^iirtum 
1 to 5 long slender spines on each lateral margin; long 
clasping fibers present; ooecia with radiating striae; straw color when 
dry: circumpolar, south to Vineyard Sound in rather deep water; 
Europe; Pacific coast. 

Family 5. GELLABUDAE. 

Colony erect, slender, cylindrical, calcareous, usually dichotomously 
branching and jointed ; zooecia in 1 or more rows, lozenge-shaped or hex- 
agonal and arranged in series around a central axis, making the branch 
cylindrical: 8 genera. 

OxLLAJtiA Lamouroux. Colony jointed, the internodes connected by 
flexible horny tubes; zocecia surrounded by a raised border; avicularia 
of simple type, resembling the ordinary zocecium; ooecia concealed, the 
opening being just above the mouth : several species. 

0. fistulosa (L.) (Fig. 415). Shape of zocecium variable; orifice 
arched above, slightly incurved below; area surrounding it minutely 
pitted; avicularium just above it and in the same line with the zocecium; 

opening of ocacium round or oral: a northern species; on rocks, shells, 
etc., from shallow to deep water. 

Family 8. FLUSTBXDAE. 

Colony horn-like and flexible, erect, expanded, and foliaceous, usually 
consisting of broad branches attached by a narrow base; zocaeia contigu- 
ous and multiserial : 6 genera. 

Futstka L. Colony frond-like ; zoceeia in 1 or 2 layers, more or less 
quadrangular in form, rounded above, with a raised margin; avieularia 


Flc. 41S — Ceilaria flatulota (Cambridge Natural History). Fit. «8 — Fl**tra foUacea 

(Cambridge Natural History). A, entire colony ; B, several aoolds. 

Fig. 417 — Mcnbraalpora pilosa (Qnburn). 

resembling the zocecium and usually in line with them; ocecia concealed: 
several species. 

F. follacea (L.) (Fig. 416). Colony brownish in color, with a dis- 
tinct odor of violets when fresh, up to 15 cm. high; nxecia in rows and 
in 2 layers with 2 spines on a aide; ooecia very shallow, the opening 
forming an arch over the upper end of the zocecium : a northern species 
occurring on atones, shells, etc., in shallow water. 


Colony calcareous or partly membranous and flattened, being in- 
crusted on stones, shells, or seaweed, occasionally erect; zomeia often more 
or leas rectangular and with raised margins : several genera, with 150 species. 

Uekbhaxipo&a Blainville. Zocecia with raised margins and a 
depressed front wall which is wholly or partly membranous, and placed 
beside one another horizontally, forming a more or less irregular crust : 12 
species near Woods Hole. 

H. pilosa (I..) (Fig. 417). Zocecia ovate, narrowed below, thickly 
punctured with minnte oval pores and often with a silvery sheen ; margin 
thickened, with 4 to 12 spines and just below it a corneous spine, some- 
times short and sometimes very long; no ocecia: on stones, etc., from tide 


lines to deep water, from Long Island Sound to the Arctic Ocean; very 
common; cosmopolitan. 

M. monostachys Busk. Colony irregular, often radiate; zooecia oval 
and elongate, with usually 6 to 10 pairs of marginal spines, of which the 
upper pair is directed upwards and the others bend inwards, often meet- 
ing in the middle; a single large basal spine is directed forwards and 
may be the only spine present; avicularia wanting; ooecia wanting: on 
stones, shells, seaweed, etc., from shallow to deep water; New Jersey to 
the Arctic Ocean; cosmopolitan. 

M. craticula Alder. Zooecia small, in regular radiating linear rows, 
oval; margin with about 14 flattish spines, of which the upper 2 are 
erect; the others extend across the cell, meeting in the middle of it; an 
avicularium often at the margin of the cell: on shells, etc., the colony 
forming small flabellate or roundish patches with a spongy appearance; 
from shallow to deep water; Arctic Ocean to Long Island Sound. 


Colony incrusting or erect; zooecia with the front wall more or less 
fissured or traversed by radiating furrows : 6 genera. 

Obibbilzva Gray. Colony incrusting; zocecia contiguous; opening 
semicircular: about 20 species. 

0. punctata (Hassall). Zooecia oval, covered with small punctures, 
often arranged in rows; 4 or 5 marginal spines with usually an avicu- 
larium on each side of the orifice; ocecia rounded: Vineyard Sound and 
northwards; in shallow water; common on shells and pebbles; Europe. 

0. annulata (Fabricius) (Fig. 418). Zocecia ovate, convex, very 
distinct, with a median keel and about 6 transverse rows of punctured 
furrows; sometimes with 3 or 4 marginal spines; colony forming small 
reddish crusts: on stones and kelp, from shallow to deep water; often 
common north of Cape Cod; Europe. 


Colony either incrusting or erect and foliaceous or dendritic; orifice 
more or less circular and with a straight lower margin and a semilunate 
or circular median pore immediately below it : 3 genera. 

Mxobofobella Hincks. Colony incrusting; orifice semicircular: 
several species. 

M. ciliata (Pallas) (Fig. 419). Colony forming a delicate, irregular 
crust with a frosty sheen on seaweed, shells, etc.; zooecia obscurely hex- 
agonal and punctate; orifice bearing 3 to 7 long spines, which may be 
wanting; median pore lunate; large avicularium on one side with an acute 


mandible often prolonged into a long, slender spine ; ooecia globose, above 
the zocecium: cosmopolitan; from tide lines to 300 fathoms. 

Family 10. MYBIOZOIDAE. 

Colony inernsting or rising in a foliaceous or dendroid expansion; 
zocBcia calcareous without raised margins or membranous area; opening 
with an indentation in the lower lip: 5 genera. 

Scrxzopobexxa Hincks. Colony incrusting, sometimes several lay- 
ers thick, or occasionally forming foliaceous expansions; avicularia 
usually lateral: over 100 species. 

8. unicornis (Johnston) (Fig. 420). Zocecia ovate or rectangular 
with a punctate surface, often silvery in appearance, an avicularium on 
one or both sides of the opening; orifice circular; ocecia globose, with 

Fig. 418 Fig. 419 Fig. 420 

Fig. 418 — CribHUna annulata (Osborn). Fig. 419 — Microporella oiUata (Ouburn). 

Fig. 420 — 8chizoporella unicornis (Osborn). 

radiating grooves; colony forms a white or reddish spreading crust: South 
Carolina to Massachusetts Bay; from tide lines to deep water, on shells, 
stones, etc.; often very common; Europe. 

8. hyalina (L.). Zocecia elliptical, arranged irregularly in radiating 
rows; surface smooth and shiny, often glassy and transparent; opening 
terminal variable in shape, sometimes without the indentation; ocecia 
globose and punctate: Long Island Sound to the Arctic Ocean from tide 
lines to deep water; on stones, etc., and often forming nodules on hydroids; 
cosmopolitan; California. 

Family 11. ESCHABIDAE. 

Colony calcareous and incrusting, or erect, being lamellate or den- 
dritic; zocecia without raised margins or membranous area; sometimes 
with secondary opening, either elevated and enclosing an avicularium or 
not: numerous genera. 

L LxPBAixa Johnston. Zocecia usually ovate, with a more or less 
horseshoe-shaped orifice which is arched above and straight and often 
narrow below; colony incrusting or foliaceous, often radiating from a 
central point: about 70 species. 


L. pallasiana (Moll) (Fig. 421). Zocecia large and coarsely punc- 
tate; orifice large, contracted on each side below the middle, often with 
an avicularium below the lower border; peristoma raised and prominent; 
no ocecia ; colonies forming large, reddish crusts : common ; 
New Jersey to the Arctic Ocean, between tide lines and in 
shallow water. 

L. pertusa (Esper). Zocecia large, swollen, punctate; 
orifice round, contracted below by 2 lateral denticles, with 
usually a tubercle below it; ocecia globose: Gulf of St. 
Lawrence to Florida, on shells, etc., from shallow to deep 
water; colored patches radiating from a common center; 
^cw'roHo 2 ' ? 0BXLU Gray. Zocecia ovate or elongate, with a 

^OsSornV* semicircular orifice, above which is a secondary orifice, 
this being elongate or more or less triangular and enclos- 
ing an avicularium; colony incrusting or erect and foliaceous. 

P. concinna (Busk). Zocecia granular, arranged in lines; orifice 
arched above, with 2 spines, frequently with a raised margin ; avicularium on 
lower tip; ocecia globose, prominent, often with a puncture 
in front: Cape Cod to Gulf of St. Lawrence, colony form- 
ing large circular reddish patches; Europe; California. 

3. Smittina Norman. Zocecia more or less quad- 
rangular, with a small circular orifice which is surrounded 
by an elevated ridge or peristome; primary orifice dentate, 
secondary orifice with a sinus in front ; colony incrusting or 
erect and foliaceous: numerous species. £m£ihm 

S. trispinosa (Johnston) (Fig. 422). Zocecia ovate, JoSJSS! 
very variable; orifice variable, usually round or pear- 
shaped, often being narrowed below, with 2 to 4 spines on young indi- 
viduals, frequently with a large avicularium at one side, occasionally 
with 1 or 2 small oval avicularia; ocecia large, globose, usually with 
2 or 3 punctures : Atlantic coast, colonies forming large 
yellow or whitish crusts; Europe; Pacific coast. 

4. M noBoxxLLA Hincks. Zocecia with a semicir- 
cular or reniform opening, the margin being elevated in 
front and with a prominent tooth below: colony in- 
crusting; about 50 species. 

M. peacM (Johnston) (Fig. 423). Zocecia rnom- 
boidal; opening large, with 6 slender marginal spines 
which may be wanting in old individuals; ocecia small: 
Long Island Sound to the Arctic Ocean, from tide lines to deep water, 
colony forming a large whitish irregular patch of solid texture; Europe. 



Zocecia calcareous, tubular, more or less erect, with a terminal open- 
ing, and irregularly heaped together; colony usually incrusting, often 
composed of many layers of cells; sometimes erect: 2 genera. 

Oellepoba Fabricius. With the characters of the family: numer- 
ous species. 

0. americana Osburn. Colony incrusting or rising in nodular 
branches a few millimeters high, growing on hydroid and bryozoan stems 
and algae; zocecia ovate, more or less erect, heaped upon one another and 
turned in various directions; orifice circular with a notch and a rostrum 
which overhangs it and an avicularium at its base: Long Island to Arctic 
Ocean; often common. 

0. pumicosa (L.). Colony massive, scabrous, composed of many lay- 
ers of pinkish color when fresh ; zocecia subcylindrical or ovate, smooth, 
erect, crowded; orifice round, with a thin, raised margin, immediately 
below which a tall rostrum bearing an avicularium is often present: 
Atlantic and Pacific coasts, covering stones and shells in shallow 
water; common. 

Suborder 3. CTENOSTOMATA. 

Opening terminal and closed by an operculum of setae set in a 
thin membrane; zooecium never calcareous but fleshy or membranous; 
no avieularia, vibracula, or ooocia: 11 families, 10 of which are marine* 

Key to the families of Ctenostomata here described: 

«x Animals marine. 
6j Colony fleshy, forming irregular, incrusting or erect masses. 

Ox Opening of zooecium not bilabiate 1. Alcyoitidiidae 

Cs Opening with 2 distinct lips 2. Flustbellidae 

b t Colony branching, either recumbent or erect 

Ox All the tentacles erect, forming a circle 3. Vesicularxidae 

c, Tentacles not in a circle, 2 being turned back 4. Valkebtioae 

a, Animals in fresh water .5. Paludicellidas 


Colony fleshy or membranous, forming either an expanded and gelat- 
inous crust on seaweed or rocks, or being erect and cylindrical or com- 
pressed; zooecia closely joined and developing by budding from one 
another and not from a stolon; opening closed by an invagination of the 
tentacular sheath: 1 genus. 

ALOTONronrM Lamourouz. With the characters of the family: 18 

A. mytdli Dalyell. Colony an extensive gelatinous crust, cylindrical 
or somewhat flattened, and irregular in shape and reddish, gray, or yel- 


lowish in color; zocBcia hexagonal, closely packed together: from the Arctic 
Ocean south to Long Island Sound, on stones, piles, crabs, etc., from tide 
lines to deep water; Europe. 

A. hirsutum (Fleming) (Fig. 424). Colony incrusting or erect, com- 
pressed, expanded, and branched, yellowish-brown or reddish in color, 
the surface covered with conical papilla, between which are the orifices : 
Long Island Sound to Arctic Ocean in shallow water, incrusting the 
stems of fucus and other plants; common; Europe. 


Colony similar to the above, but the opening is bilabiate, with a 
movable lip which acts as an operculum; larva (Cyphonautes) with a 
bivalve shell: 1 genus. 

Flttstbella Gray. With the characters of the family: 3 species. 

F. hispida (Fabricius) (Fig. 425). Colony a thick, brown crust, 
roughened by numerous reddish spines; zocecium ovate or hexagonal, with 


Fig. 424 Fig. 426 Fig. 426 

Fig. 424 — Alcyoni&ium hir$utum (Osburn). Fig. 425 — Flustrella hispida (Osborn). 

Fig. 426 — Bowerbankia gracilis (Osborn). 

a raised opening around which are one or more tall, red spines, which may 
also be present along the margin of the cells: circumpolar, south to 
Long Island Sound and Alaska, incrusting the stems of fucus, etc; 
common; Europe. 


Colony horn-like or membranous, branching, and either erect or recum- 
bent, the zooecia contracted below, budding off from a distinct stem: 
5 genera. 

1. Bowebbanxia Farre. Colony recumbent; zooecia cylindrical, in 
clusters often spirally arranged; 8 to 10 tentacles in a circle; gizzard 
present between stomach and oesophagus: 20 species. 

B. gracilis Leidy (Fig. 426). Colony creeping, the cylindrical zooids 
rising separately from the recumbent stem: coast of New England, on 
hydroids, seaweed, etc. 

2. Akateia Lamouroux. Colony erect; zooids in a double series: 
several species. 


A. dichotoma (Verrill) (Fig. 427). Colony 5 cm. or more high and 
white in color, repeatedly forking, a short, dark-brown segment being 
at the base of each fork; zooids crowded together spirally in groups of 
6 to 12 each: New Jersey northwards, on algae, rocks, etc., in shallow 
water; often common. 


Colony branching and erect or recumbent and creeping; tentacles 
8 in number, 2 of which are bent outwards towards the side and 6 are 
erect; zorecia contracted below: 1 genus. 

Vaxjcebxa Fleming. With the characters of the family: 4 species. 

Fig. 427 Fig. 428 Fig. 429 

Ichotoma (Osborn). Fig. 428 — Vc 
Fig. 429 — Paludicella ehrenbergi. 

Fig. 427 — Amathia dichotoma (Osborn). Fig. 428 — Valkeria uva (Osburn) 

V. uva (L.) (Fig. 428). Colony composed of delicate jointed tubes, 
which creep over seaweed, hydroids, or shells, or may stand erect to a 
height of 5 to 10 cm. giving off paired branches; zooids in thick clusters, 
which are principally at the base of the branches and on them: from 
New Jersey northwards, in shallow water; Europe. 


Colony with a horn-like or membranous cuticula and composed of 
delicate, jointed, branching, recumbent or partly erect tubes, which creep 
over stones and sticks in slow streams and fresh-water ponds : 2 genera. 

Key to the genera of Paludicellidae : 

a\ Zooids recumbent, not rising from stolons... 1. Paludicella 

a, Zooids erect, rising from stolons 2. Pottsiella 

1. Palttdioella Gervais. Colony consists of series of club-shaped 
zooids placed end to end and separated from one another by partitions ; 
opening lateral; branches usually paired; no statoblasts present but 
hibernacula or winter buds which persist when the rest of the colony 
has died: 1 species. 

P. ehrenbergi van Beneden (Fig. 429). Colony recumbent or partly 
erect; length of zooid 2 mm.; number of tentacles about 16: cosmopolitan. 

• See "Observatlone on Budding in Paludicella and Some O^her Bryosoa," by 
C. B. Davenport, Bull. Mas. Comp. Zool., Vol. 22, 1890. 


2. Pottsxella Kraepelin. Colony consists of stolons from which 
at intervals single erect, cylindrical zooids arise; opening terminal: 1 

P. erecta* (Potts). Length of zooid 1.5 mm.; number of tentacles 
about 20: Montgomery County, Pennsylvania. 


Lophophore oval or horseshoe-shaped; epistome present, projecting 
over the mouth; statoblasts present, which usually have a broad mar- 
ginal band of air cells called the float which sustains them in the water: 
in fresh water; 3 families and about 30 species, 7 American. 

Key to the families of Phylactolamata : 

a\ Colony branched, provided with an opaque chitinous or hyaline cuticula ; 
statoblasts without hooks. 
\ Lophophore nearly circular; statoblasts without float. .1. Fredebicelltoae 
ft, Lophophore horseshoe-shaped; statoblasts with float.... 2. Plumatellidak 
a. Colony massive, secreting a gelatinous base; statoblasts with float and 

hookB 3. Cbistateujdab 


Colony tubular, branched in form of antlers; lophophore oval; 
euticula opaque and brown, rarely gelatinous and hyaline; tentacles not 

over 24; statoblasts dark brown, elliptical, with- 
out float : 1 genus. 

1. Fhedebzoella Gervais. Colony dendritic 
and either recumbent or erect, attached either 
entirely or partially to the under surface of 
stones or sticks in ponds and streams, usually in 
dark places; lophophore oval, bearing usually 20 
Fredericeilo sultan*. to 22 tentacles: 1 American species. 
' C ° B^atatoUasp ' F. sultana (Blumenbach) (F.walcottii Hyatt; 

F. pulcherrima Hyatt; F. regina Leidy) (Fig. 
430). Form of colony differs in different localities, consisting of inter- 
twining branches which adhere to the substratum or form a dense clump : 


Colony consists either of cylindrical tubes which are either branched 
or form massive clumps or of hyaline, recumbent, lobed tubes, or of 
hyaline erect, slightly lobed sacs; tentacles 40 to 60 on a horseshoe-shaped 

* See "On Paludicella erecta/' by E. Potts, Proc. Acad. Nat Set., 1884, p. 21S. 
f See "Observations on Polyzoa, Suborder Phylactolemata," by A* Hyatt Proc 
Essex Inst., Vols. 4 and 5, 1866-1868. 



lophophore; statoblasts elliptical, without marginal hooks but with a float: 
several genera. 

Key to the genera of Plumatellidae here described : 

Ox Statoblasts oval ; zooids uniformly spaced 1. Plumatella 

a, Statoblasts lenticular ; zooids grouped at intervals 2. Lophopus 

1. Plumatella Lamarck. Colony consists of cylindrical, more or 
less branched tubes, either recumbent or erect, which lie extended on 
the substratum or form a clump ; 40 to 60 tentacles : about 20 species, 3 
American; in ponds and streams, usually not in the light; the commonest 
fresh-water bryozoans. 

P. princeps Kraepelin (P. diffusa Leidy) (Fig. 431). Colony creep- 
ing or erect, often much branched, the branches sometimes fused to- 

Fig. 432 

Fig. 431— Plumatella princeps. A, a colony (Davenport) ; B, a floating statoblast ; 
C, a stationary statoblast (Sttssw. P. Deut.). Fig- 432— Plumatella polymorpha. 
Al a colony (Da\ "- ~ ----- ^- A _w,._*. •, - «*_« 

(SOssw. F. Deut). 

C, a stationary statoblast (Sttssw. F. Deut.). Fig- 432— Plumatella polymorpha. 
Al a colony (Davenport) ; B, a floating statoblast ; C, a stationary statoblast 

gether; cuticula brown, with a keel that broadens at the aperture; 
statoblast elongated: cosmopolitan. 

P. polymorpha Eraep. (P. nitida Leidy; P. arethusa Hyatt) (Fig. 
432). Colony creeping or erect, often richly branched; cuticula usually 
transparent, rarely brown or keeled ; statoblast nearly 
circular, sometimes with angular margin: cosmopol- 

P. punctata Hancock (P. vesicularis Leidy; P. 
vitrea Hyatt) (Fig. 433). Colony creeping, often 
thickly branched; cuticula colorless, transparent, the 
elevated mouth cone being wrinkled and spotted with 
white; statoblast nearly circular: in America and 

2. LoPHOPtrs Dumortier. Colony thick, erect, 
and sometimes lobed; cuticula gelatinous; about 60 tentacles; statoblast 
with acute ends; 1 American species. 

L. cristallinus (Pallas) (Fig. 434). Colony up to 10 mm long: in 
ponds and slowly-flowing streams, chiefly on water plants; rare; America 
and Europe. 

Fig. 433 Fig. 434 

Fig. 433 — Stato- 
blast of Plumatella 

unctata (Stissw. F. 
Statoblast or Lopho- 


ut). Fig. 43< 

pus crystallinus 
(SUssw. F. Deut.). 




Colonies forming compact hyaline groups which secrete a gelatinous 
base; aperture slightly elevated above the level of the group; statoblasts 
large, about 1 mm. in diameter, provided with hooks:' 2 genera. 

Key to the genera of Cristatellidae : 

a t Statoblast with a row of marginal hooks; gelatinous base often very 

thick 1. Pbctinatklla 

a, Statoblast with 2 rows of marginal hooks ; gelatinous base forms a thin 

sole 2. Cristatella 

1. Psotzhatxzxa Leidy. Many associated colonies in rosette-shaped 

groups on a gelatinous base which may attain a 
jJL thickness in the autumn of 40 cm.; the youthful 

colony is locomotory: 1 American species. 

P. magnifica Leidy (Fig. 435). Tentacles 60 to 

jzmH ^y-/ - 84 in number; statoblasts circular, black in color, 

^Ep s with 10 to 22 marginal anchor-shaped hooks: often 

A l common on stones, sticks, etc., in ponds and streams; 

North America; introduced locally into Europe and 

2. Obistatella Cuvier, Colony an elongate, 
gelatinous mass with a thin, flat sole on which it 
creeps; the zooids are located on the upper surface 
of the colony and may contract into a common cavity; 
statoblasts circular with 2 rows of marginal hooks: 1 

0. mucedo Cuv. (C. idae Leidy; C. ophidioidea Hyatt; 
G. Iacu8tri8 Potts) (Fig. 436). Young colony circular, 
later elongate, attaining in the autumn a length of 28 
cm. ; usual length 3 to 5 cm. ; 80 to 90 tentacles ; statoblasts 
with 10 to 34 hooks in one row and 20 to 50 in the other: 
America and Europe, in ponds and sluggish streams on submerged sticks, 
pond lily leaves, etc.; not common. 

Pig. 435— Pectina- 
tella magnified (Dav- 
enport). A, a thick 
gelatinous mass sur- 
rounding a stick on 
which are numerous 
colonies ; B, stato- 

Fig. 436 

Statoblast of 



(Sussw. F. 


Subphylum 5. BRACHIOPODA.* 

Sessile, marine, mollusk-like animals in which the body is enclosed 
in a bivalve, calcareous, or horny shell, one valve of which is dorsal and 
one valve ventral. The shells (Fig. 437) can be opened and closed by 
means of muscles, the hinge end being posterior and the opening anterior 

* See "Catalogue of the Recent Spedes of the Class Brachiopoda/' by W. H. Dall, 
Proc. Acad. Nat. Sci., Phil., 1873, p. 177. "A Monograph of Recent Brachiopoda," by 
T. Davidson, Trans. Lin. Soc, 2nd ser., Vol. 4, 1886-1888. "Revision of the Families 
of Loop-bearing Brachiopoda," by C. B. Beecher, Trans. Conn. Acad., Vol. 9, 1893. 


in potation. The animal is attached to some more or leas fixed object by 
means of the peduncle, a stout, muscular stalk which is a prolongation of 
the hinder end of the body and passes either between the valves of the 
■hell or through a hole in the projecting ventral valve; in a few species 
(Cranio) the whole ventral valve is attached, no peduncle being present 
The soft parts of the body, which lie between the hinder and middle 
portions of these shells, are very short and broad, and from them two 
leaf-like folds called the dorsal and the ventral mantles extend forwards 
and cover the inner surface of the forward portion of the shells. Two 
additional projections of the anterior body wall also extend forwards and 
occupy the space between the two mantles. These are the tentacular arms 
or lophophores, a pair of ridges or of bent or coiled arms which in the 

tig. 43T— DUmin 

■bell; 3, stomach ; 4, liver ducts: •>, »uui, v, unuuc . , 
B, loptaopbore ; B, muscles ; 10, intestine ; 11. Teutral shell. 

Tetticordinea are supported by a calcareous skeleton proceeding from the 
dorsal valve of the shell. These arms are the largest and most conspicuous 
organs in the body and have given the group its name : they are respiratory 
and sensory in function, and are also of use in the ingestion of food. 
Both they and the mantles contain a cavity which is in direct communi- 
cation with the body cavity. Running along the surface of each ridge or 
arm is a ciliated groove along one side of which is a row of ciliated ten- 
tacles. By the action of these cilia the minute organisms which form the 
food of the animal are swept into the mouth. 

The month lies between the base of the arms and is without special 
jaws or lips ; it opens into a digestive tube in which an (esophagus, stom- 
ach, and intestine may be distinguished. Sac-like digestive glands (livers) 
open into the stomach. The Testicardmee have no anus: in the Ecdrdines 


the anus ifl at the hinder end of the body between the edges of the sheik. 
The nervous system consists of a pair of ganglia dorsal to the OBSophagus, 
a ventral pair, connecting commissures and radiating nerves. There are 
no special sense organs in the adult animal, although the larva may have 
eye spots and otocysts. The circulatory system consists of a heart, a large 
vein which enters it anteriorly, and arteries which proceed to the spaces 
of the body cavity. The excretory organs consist of a pair (two pairs in 
Rhynchonella) of nephridial tubes which open into the body cavity at one 
end and into the mantle cavity at the other. The sexes are as a rule sep- 
arate. The two pairs of genital glands lie near the intestine and discharge 
their products into the body cavity, whence they find their way to the 
outside through the nephridia. The larva is a trochophore, and is made 
up of three divisions, from the middle one of which the mantle folds 
develop : after a few hours of free life the larva attaches itself. 

Habits and Distribution.* —All Brachiopoda are attached to rocks, or 
other similar objects, except the Lingulidae, which live in vertical burrows 
in the sand. Most of the species live in shallow water in the neighbor- 
hood of continents : a few, however, are found in the deep sea. They are 
not generally distributed over the world but are localized, as is the case 
with many ancient groups of animals, but are often found in large num- 
bers where they do occur. Brachiopods have flourished during all the 
geological ages from the Cambrian down to the present time, the genus 
Lingula, which is still plentiful in the Indian and Pacific Oceans, being 
the oldest known genus of animals. About 2,500 fossil species have been 
discovered, mostly in the Paleozoic rocks, only about 120 living species 
being known. 

History. \— The conspicuous shells of the Brachiopoda attracted the 
attention of the older naturalists, by whom the animals were almost uni- 
versally regarded as mollusks. The name Brachiopoda was given them 
in 1807 by Dumlril. In 1873 and 1874 Morse and Kowalevsky independ- 
ently demonstrated by a study of their embryology that the affinities of 
brachiopods were not with the Mollusca but rather with the Annelida. 
Brooks held them to be Bryozoa, while Huxley and Clans placed them 
among the Molluscoidea, a subkingdom or phylum originally created by 
Milne-Edwards to contain the Bryozoa and Tunicata. Conklin and others 

• See "Observations on Living Brachiopoda/' by E. S. Morse, Mem. Boat. 8oc. 
Nat Hist., Vol. 5, 1902. 

t See "On the Embryology of Terebratullna," by B. S. Morse, Mem. Bost. Soc. 
Nat Hist, Vol. 2, 1873. "On the Systematic Position of the Brachiopoda," by B. S. 
Morse, Proc. Bost Soc. Nat Hist, Vol. 15, 1873. "On the Development of the 
Brachiopoda," by A. Kowalevsky, Abst, by A. Agassis, Am. Jour. Sd., 1874. "The 
Development of Lingula and the Systematic Position of the Brachiopoda,*' by W. K. 
Brooks, Sd. Results of Sess. of 1878, Chesapeake Zool. Lab. "The Embryology of 
| a Brachlopod," etc., by B. G. Conklin, Proc. Am. Phil. Soc, Vol. 41, 1002. 


quite recently have shown the relationship between the Brachiopoda and 
Phoronis. The affinities of the Brachiopoda are thus still obscure, but 
are undoubtedly with the Bryozoa and Phoronis. 

The subphylum contains 2 orders. 

Key to the orders of Brachiopoda: 

Ox Shell without a hinge joining the valves 1. Ecabdines 

a. The valves of the shell joined by a hinge 2. Testioasdines 

Order 1. EOABDINES. 

Shell horn-like or calcareous, the valves not being joined posteriorly by 
a hinge but only by muscles; mantles also not joined; no calcareous arms 
projecting from the dorsal valve to support the tentacular arms; anus 
present: 3 families with about 32 living and 400 fossil species, most of 
the latter being Paleozoic. 

Key to the families of Ecardines here described : 

Ot Peduncle present ; animal living in sand 1. Linguudae 

a, Peduncle not present; animal attached by ventral valve 2. Craniidae 

Family 1. LINGULIDAE. 

Shell more or less rectangular in shape, horn-like in texture, with 
valves of equal size, truncated in front and pointed behind; peduncle con- 
tractile and usually long; tentacular arms spiral, with about 6 whorls; 
mantle very vascular, with long stiff setae on the edges: 16 species, in 
2 genera, of which Lingula is found in the Pacific and Indian Oceans and 
Glottidia on both shores of America; 100 fossil species. 

Glottidia Dall. Shell smooth and linguiform; 
dorsal valve with 2 internal, sharp, incurved laminae 
diverging from the beak and extending a third of the 
length of the shell; ventral valve, with a mesial septum 
extending forwards from the beak: about 4 species, on 
both Atlantic and Pacific coasts of America. 

G. albida (Hinds). Shell narrow, oval, tapering ^ 4 38 — a \ou 
at the beak, very slightly curved in front, smooth, and (Tpyon)° rW 

white; peduncle stout and short, 45 mm. long; shell 30 
mm. long: Pacific coast from San Diego to Monterey, from low- water 
mark to 60 fathoms. 

G. audebarti* (Broderip) (Lingula pyramidata Stimpson) (Fig. 438). 
Shell narrow, tapering at the back, front margin nearly straight; color 
white, with transverse bands of green; peduncle very long and slender; 
animal hermaphroditic; length of shell 27 mm., breadth 10 mm.; length 

• See "A Study of the Structure of Lingula (Glottidia) pyramidata Stimp.," by 
H. B. Beyer, Stud. Biol. Lab., Johns Hopk., Vol. 3, 1886. 


of peduncle 16 cm.: North Carolina to Florida; in vertical burrows in 
the sand between tide lines, the contractile peduncle extending straight 
down and the opening of the shell just reaching the water. 

Family 2. CBANIIDAE. 

Shell more or less quadrate or circular in shape and without a 
peduncle, being attached by the ventral valve to a rock; dorsal valve 
limpet-like; tentacular arms free and spiral; mantle extending to the 
edges of the valve, its margin being plain : 1 genus. 

C&avxa Retzius. Shell smooth or radiately striated: 4 species. 

C. anomala (0. F. Miiller). Shell brownish in color, 18 mm. long 
and 22 mm. broad: Florida Keys and the West Indies, in 100 fathoms. 


Shell calcareous, the 2 valves being joined by a hinge; mantles also 
fused behind; ventral valve larger than the dorsal and with a beak at 
the hinder end through which the peduncle passes; tentacular arms 
supported by calcareous arms which proceed from the dorsal valve ; anus 
wanting: 3 families and about 80 species; about 2,200 fossil species. 

Key to the families of Testicar dines here described: 

Ot Shell with a sharp, hook-like beak 1. Rhynchonellidab 

a, Beak not hook-like, but prominent 2. Terkbra tuudab 


Shell more or less triangular with a sharp, hook-like beak; calcareous 
arms long and slender, curving towards each other; tentacular arms 
long and spiral: 2 genera and 8 species. 

Rhyhohohella Fischer. Shell with radiating ridges; dorsal valve 
very convex, ventral valve more flattened: 6 species. 

R. psittacea (Gmelin). Shell brown or black, 26 mm. long and not 
quite so wide: circumpolar, being found south to the Gulf of St. Law- 
rence and to the Aleutian Islands, in shallow water. 


Shell round or oval, the lower valve with a prominent perforated 
beak and 2 curved hinge teeth, dorsal valve with a hinge process and a 
slender calcareous loop: about 10 genera and 68 species. 

Key to the genera of Terebratulidae here described: 

a t Calcareous loop short 1. Terebbatulina 

o 2 Calcareous loop long. 

b x Loop with its principal stem attached but once 2. Waldeheimia 

b, Principal stem attached twice 3. Terebratella 

6, Reflected part of loop attached at the tip 4. Laqueus 




Fig. 439 — Tcre- 
bratulina septen- 
triunalis (Tryon). 

A, dorsal aspect; 

B. Inner surface 
of dorsal shell, 
showing calcare- 
ous arms. 


1. Tsbebsatuxjna D'Orbigny. Shell punctate, with 5 radiating 
striatums; calcareous loop short and forming either a perfect or a 
broken ring: 8 species; 22 fossil species. 

T. septentrionalis (Couthouy) (Fig. 439). Shell 
thin and semi-transparent, yellowish or whitish, broadly 
oval; beak projecting but little, truncated horizontally, 
with a large orifice; 13 mm. long and 8 mm. broad: 
coast of New England, in 20 fathoms off Cape Cod, at 
low-water line farther north; common. 

T. capnt-serpentis (L.). Shell oval, whitish or 
yellowish; 25 mm. long; 17 mm. wide: Europe; Florida 
and the West Indies (var. cailleti) ; Pacific coast from 
San Diego to Aleutian islands (var. unginculata) . 

2. Waldheixza King. Shell globose and smooth, 
calcareous loop composed of 2 slender branches which 
extend from the hinge almost to the front edge of the 

shell, then curve backwards to the center, where they join: 10 species; 
A 90 fossil species. 

W. floridana Pourtales. Shell triangular, gray or 
brownish-white in color; length 22 mm.; width 25 mm.; 
depth 14 mm. : Florida reefs and the West Indies, in 100 
to 200 fathoms; abundant. 

3. Tmebbatella D 'Orbigny. Shell ovoid or round; 
loop long and like Waldheimia, but with its principal 
stem twice attached: 9 species. 

T. transversa (Sowerby) (Fig. 440). Shell variable 
in shape, usually wider than long; length 30 mm.; 
breadth 38 mm.; depth 20 mm.; color from light yellow 
to dark purple: Monterey, California, northwards, in 15 
to 20 fathoms, the commonest brachiopod on the coast. 
T. spitzbergensis Davidson. Shell whitish-yellow and longer than 
wide; valves equally convex, smooth, and strongly punctate; length 9 
mm.; breadth 7 mm.; depth 3.5 mm.: circumpolar; 
south to Gulf of St. Lawrence, in 40 to 400 fathoms. 
4. Laqtoto Dall. Shell broadly ovoid; loop 
long like Terebratella, but with the reflected portion 
attached by a connecting branch on each side to the 
principal stem: 3 species. 

L. calif orniens (Koch) (Fig. 441). Shell 6 cm. 
long, 5 cm. broad, and 25 mm. deep; bright yellowish or reddish-brown 
in color : Santa Barbara County, California, and northwards, in 90 fathoms, 
being smaller towards the north. 

Pig. 440 — f ere* 
bratella trans- 
versa (Keep). 
A, natural posi- 
tion, with the 
dorsal shell 
uppermost ; B, 
dorsal aspect. 

Fig. 441 

Laqueus oalifomicus 




Subphylum 6. PHOBONIDEA.* 

Sessile, marine worms living in chitinous tubes in shallow water, which 
have at the anterior end of the body a horseshoe-shaped tentacular crown 
or lophophore. The animals are gregareous, their tubes being often 
twisted together, but without, however, communicating with one another. 
The tubes are also covered with sand, pieces of shell, etc., which give them 
a characteristic appearance. The lophophore consists of a double ridge, 
each part of which bears a single row of tentacles, its lateral extremities 
forming a spiral coil on each side. The mouth and the anus are near 

together in the middle of the lophophore, but are 
separated by a long projection of the body wall 
called the epistome. Near the anus are the paired 
orifices of the kidneys. The body cavity is large and 
is divided by a diaphragm into two parts, an upper 
or anterior, which is continuous with the cavities of 
the epistome and the tentacles, and a lower, which 
contains the viscera: the diaphragm is pierced by 
blood vessels and the oesophagus. The digestive tract 
is U-shaped, consisting of the oesophagus, stomach, 
and intestine, and is supported by longitudinal mesen- 
teries. Two circulatory fluids are present, a colorless 
fluid in the body cavity and a red fluid in a system 
of closed vessels which lie along the two limbs of the 
digestive tube and are distributed to the tentacles 
and other organs. The kidneys are a pair of tubes 
which communicate between the body cavity and the 
outside. The nervous system is subepithelial in posi- 
tion and consists of a nerve ring surrounding the mouth and nerves 
going from it to the tentacles. The animals are hermaphroditic, the 
gonads lying near the stomach and discharging their products into the 
ccelom, whence they find their way to the outside through the kidney 
pores. The development is a metamorphosis, the characteristic larva 
being known as the actinotrocha. 

The systematic position of the animals has long been a matter of 
dispute, but they are now usually placed near the Bryozoa and Brachio- 
poda. The subphylum contains a single genus and about a dozen species, 
of which two are American. 

Phobokis Wright. With the characters of the subphylum: 11 

Jig. 442 — Phoro- 
nie arohitecta — 
young individual 
with about 30 ten- 
tacles (Cowles). 1, 
epistome ; 2, lopho- 
phore ; 3, digestive 

• See "Pfaoronis architects" by R. P. Cowles, Mem. Nat Acad., Vol. 10, p. 76, 
1905. "On Phoronls pacfflca sp. nov.," by H. B. Torrey, Biol. BulL, Vol. 2, p. 283, 1901* 


P. architecta Andrews (Fig. 442). Tubes straight and about 13 cm. 
long and 1 mm. wide; anterior portion of body flesh color, posterior 
portion reddish or yellowish; tentacles about 100 in number; lophophore 
not spirally coiled at the ends: North Carolina, in sand flats near the 
low-water mark, the tubes being isolated and covered with sand grains; 
often common. 

P. paciflca Torrey. Length of tube 9 cm.; diameter 2 mm.; each 
spiral of lophophore with 1% to 2 turns; tentacles 170 to 200 in number; 
tube straight, cylindrical, incrusted with sand: Puget Sound; Humboldt 
Bay, California; in sand and mud flats. 

Subphylum 7. CBLffiTOGNATHA.* 

Elongate, transparent worms of small size which live exclusively in 
the sea, preying on other small organisms. The body is long and slender 
and unciliated, and is provided with two or three pairs of horizontal fins. 
Surrounding the mouth at the front end of the body are long, paired, 
prehensile bristles or hooks and one or two rows of small teeth (Fig. 
443, B). A large body cavity is present, which is lined with a peritoneum 
and is divided by transverse septa into three compartments. The anus is 
at the hinder end of the body and between it and the mouth lies the 
straight digestive tract: longitudinal mesenteries join the intestine with 
the dorsal and ventral body walls. The nervous system is subepithelial; 
a large cerebral ganglion forms the brain and is connected with & large 
ventral trunk ganglion in the middle of the body by commissures. The 
brain sends off nerves to the two eyes and the unpaired olfactory organ 
behind them. No special respiratory, excretory, or circulatory organs are 
present. The animals are hermaphroditic, the sex cells arising from the 
peritoneum. The two ovaries are in the middle division of the body, the 
oviducts opening near them: the testes are in the hinder division of the 
body; the spermatozoa escape to the outside through a pair of prominent 
seminal vesicles just in front of the tail fins. In the development the 
mesoderm is formed by the growth of paired pouches from the archenteric 
walls, the fused cavities of the pouches becoming the ctBlom, a process 
characteristic of many annelids and also of the Chordata. 

The Chatognatha are found in all seas, from the surface to the 
greatest depths, being often present in immense numbers. Six genera and 
about 30 species are known. 

• See "The Known Chaetognatha of American Waters/* by F. S. Conant, Johns 
Hopk. Unlr. dr., Vol. 15, p. 82, 1806. "Chartognathl," by R. von Rltter-Zahony, Das 
Tierrelcb, 1011. "Classification, etc., of the Chetognatha," etc, by E. A. Michael, 
Uhlr. of Cal. Pub., Vol. 8, p. 21, 1011. 



Key to the American genera of Cluetognatha: 

Ox Two pairs of fins besides the caudal fin 1- Saoitta 

Ob One pair of fins besides the caudal fin. 

Oj Fins near the middle ; body slender, with 1 row of teeth 2. Eukbohma 

6, Fins near the tail ; body broad, with 2 rows of teeth 3. Ptebosagitta 

1. Saoitta Quoy and Gaimard. Slender worms with 2 
pairs of lateral fins: about 25 species. 

8. elegans Verrill (Fig. 443). Length up to 3 mm.; 9 to 
12 oral hooks; anterior teeth 4 to 8; posterior teeth 6 to 9: 

North Atlantic. 

8. hexaptera D'Orbigny. Length 6 mm.; oral hooks 5 

to 10; anterior teeth 3 to 4; posterior 
teeth 3 to 5: Martha's Vineyard; cos- 

2. ExnotOHHiA Ritter-Zahony. A 
single lateral fin on each side near mid- 
dle of body; body slender: 3 species. 

E. hamata (Mobius). Length 4 
mm.; oral hooks 8 
to 10; 15 to 28 
teeth in a single 
row ; ovary reddish : 
cosmopolitan; Mar- 
tha's Vineyard, 
3. Ptebosagitta Costa. Body broad; a single 
pair of lateral fins near the tail; an expansion of 
the integument extending along the side of the body 
in front of each lateral fin to the head: 1 species. 

P. draco (Krohn) (Fig. 444). Length 10 mm.; 
oral hooks 4 to 10; anterior teeth 6 to 9; posterior 
teeth 12 to 18; forward of the middle of the body Pterotagitta draco 

, -j . i ii *i , ,.. (Cambridge 

on each side is a bundle of long setae : cosmopolitan. Natural History), 

Fig. 443 — Sagitta elegans (Zahony). 
A, entire animal ; B, nead. 1, pre- 
hensile hooks ; 2, teeth ; 3, month ; 
4, ventral ganglion ; 5, female gen- 
ital organs; 6, anus; 7, female 
genital pore; 8, male genital pore. 

Subphylum 8. SIPUNCULOIDEA. 

Marine worms which, together with the Echiurida, are often included 
in a class of the Annelida called the Gephyrea. This is a name given 
them by Quatrefages (1847) to signify the belief that they bridge the 
gulf between the Annelida and the Echinodermata, the earlier zoologists 
having grouped them with the holothurians. The total lack of segmen- 
tation, however, at any period of the life of most of the Sipunculoidea, 
and the absence of metameric organs, have made it necessary to remove 
them from the Annelida, although the fact that they pass through the 


troehophore stage indicates a dose connection with the immediate ancestors 
of that group. 

The Sipunculoidea are more or less elongated worms, the largest of 
which are 20 cm. or more in lengthy which live in the sand or mud, either 
free or in tubes or snail shells. The body is cylindrical and very con- 
tractile, unsegmented and not ciliated, and without metameric ap- 
pendages, spines, or bristles; it is made up of two divisions, a usually 
slender anterior portion called the introvert, which can be invaginated, 
and the thicker hinder portion. The subphylum contains two classes. 

Key to the classes of Sipunculoidea: 
a, Body elongate; anus at base of introvert; tentacles usually present 


«, Body robust ; anus at hinder end ; no tentacles 2. Priapulida 

Class 1. SIPUN0UL1DA.* 

Elongated worms with short, hollow tentacles at the forward end 
which are either distinct or more or less united and usually surround the 
mouth, and with the anus in the dorsal surface near the base of the intro- 
vert. The body wall consists of a cuticula, a single-layered hypodermis, 
and the muscles. The hypodermis gives rise to large glands which lie 
beneath it, in certain species enveloped in a gelatinous connective tissue 
called the cutis, and open through the cuticula to the outer surface. The 
muscles consist of an outer circular and an inner longitudinal layer and 
between them delicate oblique muscles, which, however, are not present in 
the introvert. The longitudinal muscles in certain species (Sipunculus) 
are split up into regularly recurring bundles, which produce a lattice-like 
effect (Fig. 446). The body cavity is voluminous and is bounded by a 
ciliated peritoneal lining; it contains a corpusculated blood fluid. Two or 
four retractor muscles extend back from the front end of the base of the 
introvert, by means of which invagination is effected. The digestive system 
consists of a narrow tube of about the same diameter throughout, which 
extends from the mouth at the front end to near the hinder end of the 
body, then turns on itself and extends forward to the anus. The two 
limbs of the intestine are usually twisted spirally together, in certain 
species around a single muscle strand called the spindle muscle. A blood 
vascular system is present in form of an oesophageal ring canal, tentacular 
canals which extend from the ring canal into the tentacles, and one or two 
contractile caeca (hearts) which extend from the ring canal a short dis- 
tance along the oesophagus. These organs contain a fluid which serves to 
extend the tentacles, which are probably respiratory as well as sensory in 

• See "Die Slpnncnllden," by B. Selenka. In Relsen lm Arch. d. PhlUpp, yon C. 
Semper, 1883. "The Slpnnculids of the Eastern Coast of North America,'* by J. H, 
Geroald, Froc U* S, Nat. Mu*., Vol. 44, p. 873, 1918., 


function. A pair of nephridia, called the brown tabes, opens to the out- 
side near the anus. The nervous system consists of a cerebral ganglion 
on the dorsal side of the oesophagus, which is connected by a pair of 
commissures with an unsegmented ventral nerve; this nerve passes to the 
hinder end of the body, sending off numerous nerves which are not regu- 
larly paired. A pair of simple eyes, pigmented or not, lies within the 
brain. A ciliated canal extending from the surface to the brain and called 
the cerebral tube, the walls of which are pigmented in certain species, 
is present just back of the tentacles : tactile organs are also often present 
The sexes are separate, but alike in appearance. A pair of gonads de- 
velops in the peritoneum upon the base of the retractor muscles which 
discharge their products into the body cavity, whence they make their way 
to the outside through the nephridia. The young animal passes through 
an active free-swimming stage. The metamorphosis is not accompanied 
by any well-marked evidences of metamerism, and the adult worm is still 
trochophore-like, indicating that the animals are very primitive forms 
near the base of the annelid stem. The animals live in the sand and mud, 
which they swallow in large quantities. They are found in almost all 
parts of the world, mostly in shallow water. The class contains about 11 
genera and over 100 species, 16 of which have been found on the east and 
* 4 on the west coast of this country. 

Key to the genera Sipunculida here described : 

Ox Longitudinal muscles divided into bundles (except Phatcolosoma gouldi). 
&t Tentacular fold instead of tentacles; no papillae on trunk.. 1. Sipuncxjlus 
6, Isolated tentacles present. 

0i Tentacles encircle the mouth 2. Siphonosoma 

c, Tentacles in a crescent dorsal to mouth 3. Phtscosoma 

a, Longitudinal muscles not split into bundles (with Phascolosoma gouldi), 

bx Worms free-living with numerous tentacles. .* 4. Phasoolosoma 

6, Worms inhabit tubes or shells 5. Phascolion 

1. SiPUVODXtrs L. Mouth surrounded by a fluted tentacular fold, 
without isolated tentacles, behind which is the cerebral tube; no hooks on 
the introvert; longitudinal muscles in 17 to 41 distinct bundles, giving a 
lattice-like effect; 4 retractor muscles; rectum with 1 or more cseca; 2 
contractile hearts : 16 species, mostly of large size, in most seas. 

8. nndus* L. (Fig. 445). Body up to 21 cm. long; the anterior 
sixth covered with papillae; 13 longitudinal muscles: Beaufort, North 
Carolina; Key West; Europe. 

2. Siphohosoxa Spengel. Similar to Sipunculus but with integu- 
mental blind sacs and a statocyst near the tentacles ; cerebral tube a shallow 
pit: several species. 

* See "On Borne Points on the Anatomy and Histology of Sipunculus Buflus L»," 
by H. B. Ward, Bull. Has. Comp. Zool., Vol. 21, p. 143, 1891. 



Fig. 44B — Sipuncultn 

bod; with tbe Introvert 

ei leaded (Ward). 

(Keierstein). Longitudinal mnscles 21; body cavity 
divided by septs into regular subdivisions as in an annelid ; oral tentacles 
present: North Carolina; Florida; Philippines. 

S. Phyboosoxa Selenka, Body covered with 
papillae; usually 4 retractor muscles; introvert 
with hooks arranged in rings; tentacles numer- 
ous, not surrounding the mouth but lying above it, 
forming a horseshoe; longitudinal muscles as in 
Sipunculut; eye spots present: about 27 species, 
mostly tropical. 

P. agasaiii Keferstein. Body np to 4 era. 
long and 10 mm. thick; introvert as long as 
body; about 20 rows of broad hooks just back 
of tentacles, of which there are 20; 25 longi- 
tudinal muscles: Pacific coast, Vancouver tc 

4. Phascolgsoica F. S. Leuckart. Longitu- 
dinal muscles usually not split up into bundles but 
forming a continuous sheath; mouth surrounded by 
one or more concentric circles of finger-shaped ten- 
tacles; 2 or 4 retractor muscles in the introvert: 
over 25 species, cosmopolitan, some species living 
in the shells of snails. 

P. gonldi* (Pourtales) (Fig. 446). Body with 
longitudinal muscles not forming a continuous sheath 
but split up into about 30 anastomosing bundles; 
length 18 cm., the anterior quarter of which is pro- 
boscis; skin smooth; tentacles very numerous, in sev- 
eral rows; a pair of pigmented ocular tubes open 
into the cerebral organ : Long Island Sound to Massa- 
chusetts Bay. 

P. oremita (Sars). Body with transverse ridges, 
2 to 6 cm. long and 5 to 12 mm. thick; introvert 
nearly as long as body, without books; 2 retractor 
muscles ; no spindle muscle ; 20 to 40 tentacles : 
Massachusetts coast northwards, in 40 to 1,000 fath- 
oms; Arctic Ocean. 

5. Phabcolioh Theel. Small forma living in 
tubes or in small shells; tentacles numerous, form- 

ing. 446— Dinec- 
ttou of Pkatcoloioma 
i/ouldi (KlDBBley). 1, 


nerve chord ; 8. 

! 5, I 

* See "Notes In tbe Anatomy at the Slpnncnlni gonldll Ponrtalea," by E. A. 
Andrew*. Stud. Biol. Lob. Johns Hopkins OntV., Vol. 4, p. 388, 1SB0. "The Develop- 
ment of Pbaicoloaoma," by J. H. Qeronld, ZooL Jabrb. Abt t. Anat, etc.. Vol. S3, 
p. 77,1*06, 


ing a single circle around the month; alimentary canal not spiral or 

incompletely so; no spindle muscle; 2 retractors; but 1 brown tube: 15 

to 20 species. 

P. strombi (Montagu) (Fig. 447). Body 30 mm. long, with papillae; 

a band of minute hooks back of tentacles, and large, dark-brown, cres- 

centic or triangular hooks pointing forwards on the 
hinder part: common in 2 to 1,000 fathoms from the 
West Indies to the Arctic Ocean; Mediterranean; the 
worm lives in a snail shell, closing the aperture by means 
of sand cemented into a Arm mass, leaving a hole through 
which the introvert is thrust out, and moves about car- 
rying the shell with it; common, there being many 
Phatcoiion varieties, some of which form a thick short tube of mud 

strombi , _ 

(Gerould). and sand. 


Body without tentacles; anus at the hinder end; introvert plump 
and covered with rows of small spines; trunk striated transversely and 
in most species bearing 1 or 2 large caudal appendages with respiratory 
papillae; alimentary canal in most cases straight and wide; pharynx 
muscular, provided with numerous teeth; main nervous system sub- 
epithelial, consisting of a ring around the mouth and a ventral cord 
without definite ganglia; no special sense organs, blood-vascular system, 
or nephridia in the adult, but in the young worm nephridia are present 
which open into the genital ducts ; sexes distinct ; gonads paired ; genital 
ducts open to the outside near the anus : 2 genera and 6 species, which 
are found in shallow water in the colder seas, where they burrow in the 
sand and mud. 

PttiAPXTLXTS Lamarck. Caudal appendages, covered with hollow 
papillae present; introvert thicker than the trunk, about a quarter as 
long as it and with spines in longitudinal rows : 5 species. 

P. caudatus Lam. Length 2 to 18 cm-, color yellow or brown: 
Arctic seas. 

ANNELIDA/ (The Annelid Worms.) 

Elongated, segmented worms in which a distinct head, a ccelom, and 
a digestive tube are present, and the paired appendages, where present, 
are not segmented. 

External Structure.—The segmentation, which is the most character- 
istic feature of annelids, is approximately equivalent (Fig. 461, A). 
This is the most pronounced in the Chcetopoda, in which it affects both the 
inner and the outer structure, the segments or somites being separated 
from one another by muscular partitions called dissepiments; in the 
Eirudinea and the Myzostomida the internal structure is also completely 
segmented but the rings which appear on the outer surface may not mark 
the somites; in the Echiurida the larval worm alone is segmented. 

A head is more or less distinctly marked in most annelids and contains 
the mouth, the brain, and also often tentacles, cirri and palps, which 
may have a tactile and often a respiratory function; eyes are also often 
present. The head is typically composed of two divisions (Fig. 459), the 
prostomium and the peristomium or metastomium. The first of these 
divisions is a distinct projection which forms the anterior end of the 
animal; it lies in front of the mouth (Fig. 450, A) and contains the brain 
and the eyes, tentacles, and palps, if these are present. The second con- 
tains the mouth, which is ventral in position, and often cirri, and is con- 
tinuous with the segmented trunk, in many annelids appearing as a 
part of it. 

Paired, segmental appendages, which in the annelids are muscular 
projections of the body wall and are called parapodia, are present in the 
Polychata and the Myzostomida, and all annelids except the Hirudinea, 
most Arckiannelida, and the Discodrilidae, possess paired, segmental groups 
of bristles, which are called setae and assist in locomotion. The parapodia 
are locomotors, respiratory, and tactile in function. The Hirudinea and 
a few other groups possess suckers, which assist in locomotion. 

The outer surface of the body .of annelids is a cuticula and is usually 
not ciliated in the adult worm. 

• Bee "Invertebrate Animals of Vineyard Sound," by A. E. Verrlll, Rep. IT. 8. 
Com. Fish, for 1871-72. "Preliminary Account of the Marine Annelids of the Pacific 
Coast" etc., by H. P. Johnson, Proc. Cal. Acad. Scl. (3) f Vol. 1, 1897. "A Biological 
Surrey of the Waters of Woods Hole and Vicinity," by F. B. Sumner, et al., BolL Bur. 
Fish., Vol. 31, 1913. 



Internal Structure.— The body wall consists of the cuticula, which 
forms the outer covering, the hypodermis, a single layer of cells which 
secretes the cuticula, and two layers of muscle fibers, an outer circular 
and an inner longitudinal layer. In the Hirudinea and Myzostomida the 
body cavity is filled more or less completely with a vacuolated connective 
tissue and muscle fibers, similar to the parenchyma of the Plathelminthes. 
In other annelids a spacious body cavity is present, which is usually 
divided by the dissepiments into as many separate spaces as there are 

The mouth leads into the pharynx (Fig. 487,5), which in most anne- 
lids can be thrust out through the mouth to form a proboscis, and 
is the means by which the animal takes its food. An oesophagus is 
usually distinctly marked and is followed by the intestine, which in most 
cases is straight and passes to the anus at the hinder end of the body ; in 
many annelids a pair of lateral intestinal pouches is present in each 
somite and a dorsal and a ventral longitudinal mesentery joins the intestine 
with the body wall. 

A well-developed system of blood tubes (Fig. 487, 7) is present in all 
except the lowest annelids, which often carry red blood, the most impor- 
tant of which are a dorsal longitudinal tube just above the intestine, a 
ventral tube just beneath it, and transverse tubes placing these in com- 
munication with each other. The body cavity has also a circulatory fluid 
of its own which in many annelids is in open connection with the blood 

The excretory system (Fig. 479,6) consists typically of a pair of 
coiled tubes called kidney tubules or nephridia in each somite. Each neph- 
ridium opens into the body cavity by the ciliated nephrostome at one end 
and to the outside through a pore in the body wall at the other. Respira- 
tion is carried on through the entire outer surface of the body. In the 
Polychceta, however, special respiratory organs are present in the form of 
projections of the parapodia or the appendages of the head. 

The nervous system (Fig. 479) consists of paired, segmental, ven- 
trally situated ganglia and a pair of longitudinal nerves joining them. 
The anterior ganglionic mass constitutes the brain ; it is dorsal in position, 
being situated above the pharynx in the prostomium. In their most 
primitive condition these two longitudinal nerves are separated from each 
other, but in most annelids they lie close together, forming a single strand. 
Special sense organs exist in a variety of forms. Tactile organs in the 
form of the paired appendages of the head and trunk characterize the 
polychrots and the Myzostomida; in the oligochats and leeches the entire 
forward portion of the body is highly sensitive. Eyes are present in 
polychets and leeches, and a few of the former also possess lithocysts. 


In the unisexual annelids (most polychsets) the reproductive organs 
are not well marked except during the period of breeding, when they 
appear as specialized portions of the peritoneum. The hermaphroditic 
annelids on the other hand have a complicated system of reproductive 
organs (Fig. 479). The unisexual forms are mostly born in the form of 
the trochophore larva, which goes through a complicated metamorphosis 
before reaching the condition of the adult : in the hermaphroditic annelids, 
the development is usually direct, the young worm when born having the 
form of the parent The body of the typical, primitive annelid may be 
divided into two portions, the prosoma, or the primitive head, and the 
metasoma, or the primitive segmented trunk. The trochophore larva, 
which in most cases is supposed to represent the prosoma alone, is a 
simple unsegmented animal, the metasoma not yet having made its appear- 
ance. The metasoma soon begins to grow, however, at the posterior end 
of the prosoma, the segments or somites developing one after the other as 
the worm increases in length, until in some cases a hundred and fifty or 
more may be present in the adult worm. In the higher annelids the 
prosoma annexes one or more of the anterior somites of the trunk and 
forms thus a head of increased size and complexity in which we can dis- 
tinguish the two divisions already mentioned, the prostomium and the 

In the hermaphroditic annelids, which have a direct development, 
these processes go on in the egg and the young worm is born with its 
definitive form, although usually not with the full number of somites. 
Many annelids reproduce also asexually by transverse divisions or by 
serial or even lateral budding. 

Distributions and Habits.— All annelids live in the water or in moist 
places on the land or in the earth, the majority being marine. Most of 
them are predaceous animals, although the oligochets live chiefly on veg- 
etable substances. The leeches are either predaceous or parasitic and the 
Myeostomida are exclusively parasitic. 

History.— It was Cuvier who, in 1798, first called attention to the 
fundamental difference in structure between the higher and the lower 
worms, and Lamarck who gave the former the name Annelides. Savigny 
(1820) subdivided the group into the Annelides nereideae, serpuleae, lum- 
bricineae, and hirudineae, and may be considered the founder of the 
modern classification. Milne-Edwards (1834) introduced the subdivisions 
Annelides errantes, tubicoles, and terricoles, which for sixty years or more 
had a place in the system, and Grube (1851) the subdivisions Polychceta 
and Oligocholia, which are still in general use. In more recent times 
Ehlers has been perhaps the most active in the development of the system. 

The phylum contains about 4,500 species grouped in 4 classes. 


Key to the classes of Annelida: 

Oi No suckers or sucker-like organs present (except in die DiieodrUidae) ; 
segmentation usually distinct externally. 
&! No setae (except in Chatogordius) or parapodia present. 1* Abchtanhilida 

o a Setae present 2. Chjttofoda 

Of Suckers or sucker-like organs present. 
b t Body ringed externally with a terminal sucker at each end ; leeches. 

3. Hibudinea 
Ob Body flat and oval in shape with 5 pairs of parapodia and 4 pairs of 

sucker-like organs ; parasites on echinoderms .4. Mtzostoioda 


Primitive, marine worms of small size, which are probably near the 
base of the line of the Annelida, having many characters which ally them 
to larval polychets: 2 isolated, genetically unrelated families. 

Key to the families of Arehiannelida: 

Ox Body with 5 or 6 segments, marked by ciliated bands 1. Dinophiudae 

Ob Body with numerous segments • 2. Polygobdiidae 


Minute, marine worms living among seaweed; body short, thick, and 
cylindrical, and made np of a head or prostomium, a trunk consisting of 

5 or 6 segments, and a telson or tail; head with a pair of 
eyes, 2 bands of cilia and tactile bristles, no tentacles 
being present; each segment with 1 or 2 bands of cilia; 
ventral surface also ciliated; sexes separate and develop- 
ment simple, the worm becoming adult at a stage resem- 
bling a polychaatous larva: 1 genus and about 9 species, 3 

DnronxLm Schmidt With the characters of the 

D. pygmJBUB Verrill. Length .7 mm.; width J.6 mm.; 

trunk segments 5; color whitish: Woods Hole, on piles. 

Fig. 448 D* gardineri A. Moore. Color orange red; trunk seg- 

D contain? ments 6; body ciliated in addition to the ciliated bands: 

(Nelson). Woods Hole, in brackish pools. 

D. conklini Nelson (Fig. 448). Length J5 to 1 mm; colorless; trunk 
segments 6: New Jersey coast. 


Small, marine annelids in which the segmentation is completely 
equivalent and often indistinctly marked externally or not at all, and 

• See "Dtaophttidae of New England," by A. E. Verrill, Trans. Conn. Acad., VoL 
8, p. 457. "The Morphology of Dinophllns conklini n. sp. f " by J, A. Nelson, Proc* 
Acad. Nat SdL, Pblla., Vol. 59, p. 82, 1907. 



Fig. 440 

Larva of 




which have no parapodia and usually no segmental setae; head com- 
posed of prostomium and metastomium, the former lying in front of 
the mouth and bearing a pair of tentacles, the latter larger than the 
prostomium and without appendages; body cavity, 
digestive, excretory, and vascular systems typically 
annelidan in character; nervous system subjacent to 
the hypodermis and without distinct ganglia; animals 
unisexual, the genital products developing from special- 
ized regions of the peritoneum during the breeding 
season; young born as trochophore larvae: 2 or 3 
genera; the larvae are common in the plankton at many 
places along the Atlantic coast, but with the exception 
of Chatogordim no adult worms have been found. v 

L PoLXeoSBim Schneider. Body filiform; segmentation indistinct 

at the forward end but more distinct at 
the hinder; tentacles short; anal segment 
enlarged: about 6 species. 

P. appendicular* Fraipont (Fig. 
449). Length 20 mm.; body salmon color; 
2 long anal appendages present: Atlantic 
coast (only larval forms heretofore 
found); Mediterranean. 

2. OKBTOGOBDXTOf Moore. Segmenta- 
tion as in PolygordiiM; hindermost 10 or 
12 segments setigerous; no anal enlarge- 
ment: 1 species. 

0. canaliculatus Moore (Fig. 450). Length 30 mm.: among marine 
oligocluBts on Cape Cod. 

Class 2. OHATOPODA4 

Segmentation distinct, except in the Echiurida, both internally and 
externally; setae segmen tally arranged in groups on the parapodia, where 
these are present, or sunk in pits on the integument: 3 orders. 

• Bee "On the Rearing of the Larvae of Polygordlns appendlculatus and the 
Occurrence of the Adult on the Atlantic Coast of America," by B. P. Cowles, BloL 
Bull., Vol. 4, p. 125, 1908. 

t See "A New Generic Type of Polygordlns," by J. P. Moore, Am. Nat, Vol. 38, 
p. 519, 1904. 

t Bee "Annelida Chstopoda of New Jersey," by H. B. Webster, Thirty-second Rep. 
N. Y. St Mus. Nat Hist, p. 128, 1879. "New England Annelids," by A. B. Verrill, 
Trans. Conn. Acad., Vol. 4, p. 285, 1881. "The Annelida Chstopoda from Province- 
town," etc, by H. B. Webster and J. B. Benedict Rep. Com. Fish, for 1881, p. 699, 

1884. "The Annelida Cbetopoda from ESastport Maine," by same, same jour, for 

1885, p. 707, 1887. "The Annelida Chetopoda of Beaufort N. C," by B. A. Andrews, 
Proc. U. B. Nat Mus., VoL 14, p. 277, 1891. "Polycheta of the Paget Sound Region/' 
by H. P. Johnson, Proc. Boat Boc Nat Hist, VoL 29, p. 381, 1902. 

Fig. 450 — Gh<Btogordiu9 oana- 
HoukUus (original drawings by 
J. P. Moore). A, anterior end; 
B, posterior end. 



Fig. 451— Diagram of parapodla 
(Cambridge Natural History). A, 
Nephthys: B, Ampblnome; C, Gly- 
cera; f>, Syllls; E,Leodice; F, Phyl- 
lodoce. 1, notopodium ; 2, neuropo- 
dium ; 3, cirrus. 

Key to the orders of Chatopoda: 

Ox Segmentation distinct 
6 & Parapodia with complex groups of setae ; usually cephalic appendages 

present ; mostly marine 1. Polychjeta 

ft, No parapodia or cephalic appendages present; mostly fresh-water or 

terrestrial 2. Oligochjeta 

Ob Segmentation indistinct or wanting in adult; marine 3. ECmumuA 


Mostly marine annelids, either free- 
swimming or sedentary, which are pro- 
vided with parapodia. Two portions 
may usually be distinguished in the 
parapodium (Fig. 451), the dorsal no- 
topodium and the ventral neuropodium, 
both of which may contain setae; two 
cirri, a dorsal and a ventral, extend 
from it. In the sedentary polychets 
the parapodia are much reduced in 
size on either the whole or a part of 
the body and in a few they are entirely 
The polychffits have a distinct head which is usually provided 

with special sense organs (Fig. 452). The prostomium may bear ten- 
tacles, which may number from one 

to ten and are dorsal in position, 

and two palps which are ventral 

and in certain forms are broken 

up into long respiratory filaments. 

Elongated peristomial cirri may 

also be present. Eyes are often 

present on the prostomium and 

lithocysts are found in a few forms 

{Arenicola). The mouth is in the 

peristomium and is often provided 

with a proboscis. Polychaets are 

often highly colored; bright red, 

green, blue, and yellow tints char- 
acterize many of them and make 

them very beautiful animals. 

Polychaets are usually born as 

trochophore larvae and pass through a metamorphosis before reaching 

the adult stage. Many reproduce asezually by serial or even lateral 

Fig. 452 — Diagram of the heads of 
various polychets (Cambridge Natural 
History). A, polynold; B, syllld; C, 
Nephthys; D, Leodlce: E, Phyllodoce; 
F, Trophonla. 1, prostomium; 2, peri- 
stomium ; 3. tentacles ; 4, palps ; 5, 
peristomial cirri. 


budding. In many the anterior part of the body is sexless and is called 
the atoke, while the hinder part is sexual and is called the epitoke, these 
two portions being different in appearance; in some the epitokes break 
off from the atokes and swim about independently, while the atokes bud off 
new epitokes. The palolo worm of the Samoan and Fiji Islands is the 
epitoke of Leodice viridis, which comes to the surface in great numbers at 
the full of the October moon to breed, and which are caught by the natives 
for food. The palolo worm of the Atlantic is L. fucata. In Syllis the 
epitoke forms a new head; in Autolytus this happens before separation. 

In certain species of Nereis heterogony is present, a small pelagic 
form alternating with a large one which lives at the bottom. 

Distribution and Habits.— A very few polychets live in fresh water 
(Manayunhia in the Schuylkill, a Nereis in California, and several others) ; 
the remainder, which are marine, are almost all bottom animals which 
burrow in the sand or in rocks or live in tubes they have built for 
themselves of lime or other material. They are found at all depths and 
are usually numerous in all parts of the world. The free-swimming poly- 
chats are predaceous animals, while the sedentary ones live on all kinds of 
organic substances; a few are parasitic, and a number commensalistic. 

The order contains about 39 families and 2,500 species grouped in 7 

Key to the suborders of Polyehceta : 

a* Worms free-swimming or burrowing, a few tubicolous ; head distinct, with 

tentacles and palps 1. Nebeidifobmia 

a, Worms tubicolous or burrowing; head not so distinct and not provided 
with both tentacles and palps ; sometimes with neither. 
&! Peristomium does not project forwards in form of a collar. 
c t Head with gill filaments (except in Cirratulidae) . . . .Z. Tebbebezxifobmia 
c, Head without gill filaments. 

dx One pair of long peristomial cirri present 2. Spionifobmia 

d, One pair of retractile tentacle-like organs on head.. 4. Capitellifobmia 
dj Head with no appendages (except in ChlorhcBmidae) ... .5. Scoleoifobmia 
5 t Peristomium projects forward in form of a collar. 

Ct Peristomial collar not setigerous 6. Sabellifobicia 

c, Peristomial collar setigerous 7. Hebmellifobmia 

Suborder 1. NEREIDIFORMIA.* 

Well-developed tentacles and palps present; peristomial cirri almost 
invariably present ; parapodia well developed, with internal skeletal rods 
called acicula and ventral and dorsal cirri; proboscis present, often 
with prehensile hooks; worms predacious, a few forming tubes: about 
13 families. 

• See "Die Borstenwarmer," by B. Bblers, 1864. 


Key to the f amiliea of Nereidiformia here described : 
a, Back partial); or totally covered with broad, overlapping scales. 
•. But .Mom k. ,cl<,. '■ <■"■" 

6, Dorsal cirri broad and leaf-like, overlapping one another, but not cover- 

■ ing the back 2. Phyixodocidak 

6, Cirri not broad and leaf-like. 

o, Dorsal cirri usually long and slender; asexual budding usual. .3. Stliidak 
c, Dorsal cirri not very long ; asexual reproduction unusual. 
dy Prostomlum not simulated. 
«, No large teeth or jaws on proboscis. 

/, Proboscis simple ; parapodia usually uniramous 4. Hesionidae 

/, Proboscis divided into lobes ; prostomium small and acute. .9. Awciidae 
e, Two or more large teeth or jaws usually on proboscis. 
/, But 1 pair of jaws ; 1 pair of tentacles, 1 pair palps and 4 pairs 

peristomial cirri 5. NniPAl 

/, Two or more pairs of Jaws. 

g, One pair of doraal and 1 pair of ventral jaws 6. Nkphthtdidak 

g. Jaws form a complicated apparatus 7. Leodicidae 

d, Prostomium annulated ; tentacles inconspicuous ; proboscis very large. 

8. Glyceeiuae 
Family 1. APHEODITroAE. (FiO. 452, A.) 

Worms with imbricated scales (elytra) on the back, mostly on alter- 
nate segments, which may take the place of dorsal cirri; slender dorsal 
cirri usually alternate with tbe scales; head 
with usually 3 tentacles and 2 long palps: 
numerous genera and species. 

Key to the genera of Aphrodilidae described : 
ti, Body with felt-like bristles on sides and back 

concealing the elytra 1. Aphbodtta 

a, Body without this felt. 
6, Bod; with but few pairs of elytra, 
o, Prostomium prolonged Into the base of the 
lateral tentacles ; 12 pairs of elytra. 

o, Prostomium produced forward into a pair 
of pointed tips, quite free from tbe base 

of tbe tentacles 3. HadcothoK 

b, Body with numerous pairs of elytra. 

o, Over 40 pairs present 4. PholoE 

c, Over 100 pairs present 6. SthKWelaIb 

1. Aj? hhodita L. Body elliptical, with 15 
. „.*!»'- *J S ,„ , pairs of elytra; entire back covered by the 

Aphrodita hastata (Moore). r J ' * 

long felt-like setae arising from the notopo- 
dium; strong dorsal setae also present, projecting through the felt; 1 
short tentacle and 2 long palps on the head: about 15 species, 2 in tbe 
Woods Hole region. 

A. hastata Moore (Fig. 453). The Sea Moose. Body short, wide, 
and thick, the sides and back covered with the iridescent felt; dorsal 


setae carve over the back to the middle line where they end in books; 
length 12 cm.; width 4 cm.: Vineyard Sound, in from 10 to 100 

2. Lxptdokotttb Leach. Body broad, with nearly parallel sides, 
and 12 pairs of elytra; head with 3 tentacles, 2 long palps, and 2 pairs 
of peristomieJ cirri; eyes sessile: under stones near tide 

lines; 2 New England species. 

L. sgnamatus (L.) (Fig. 454). Elytra tuberculated; 
color dark brown ; length about 3 cm. ; width 8 mm. : very 
common from New Jersey to Labrador; Europe. 

L. snhlevis Verrill. Elytra smooth; color light brown 
or gray, with spots; length about 3 em.; width 7 mm.: 
Virginia to Massachusetts; not so common as the above. 

3. Hahmothob Kinberg. Body flattened and elon- 
gate, with 15 pairs of elytra; head bilobed and with 3 

tentacles, 2 long palps, 2 pairs of peristomial cirri and 4 Lg^SoiofiM 
eyes; segments completely or nearly covered by elytra: 'ivereiii)* 
2 New England species. 

H. imbricata (L.). Color variable, grayish or brownish, sometimes 
with a black dorsal stripe; 42 to 44 segments; 2 to 3 cm. long: Long 
Island to Greenland; from low-water mark to 60 fathoms; Europe; 
North Pacific. 

H. acnleata Andrews (Fig. 455). Surface covered with spines; 34 
segments; length up to 2 cm.: the com- 
monest seale annelid at Beaufort, N. C; 
under stones, etc., in shallow water. 

4. FHOLOI Johnston. Body with 
less than 70 segments and with numer- 
ous pairs of elytra which alternate with 
the dorsal cirri anteriorly but occnr on 
every segment posteriorly; 2 pairs eyes; 
short peristomial cirri; 1 tentacle: 


Pig. 455 Fig. 456 

Fig. 45H — HarmothoB acutaum — . , . .. _ , , 

b«ad with extended proboscis (An- several species, 1 in New England. 

drewB). l, proboscis ; 2, palp ; S, — __, _. ,_, , . . ,_,. ,__, 

tentacles; 4, peristomi.l cirri : li' P. mlnnta (FabnClUS) (Fig. 450). 

proitomiam. Fig. 456 — Pholot » T __. . . . . ,. , . „ 

minuia (Lennia). Number of segments in adult about 68; 

number of pairs of elytra 44; length 
2 cm.: Cape Cod, and northwards; in shallow water; Europe; North 

G. St u b mi .a ia Kinberg. Elongated worms with numerous seg- 
ments (over 100) and but 1 tentacle; 2 pairs eyes; elytra very numer- 
ous, alternating with dorsal cirri anteriorly but on every segment pos- 
teriorly : many species, 2 in the Woods Hole region. 


8. leidyi Quatrefages (S. picta Verrill). More than 150 pairs of 
elytra present ; color grayish with a mid-dorsal stripe ; head brown with 
a central red spot and a white spot on each side; length 15 cm.; width 
4 mm.: North Carolina to Massachusetts Bay, in shallow water. 

Family 2. PHYLLODOdDAE. (Fio. 452, E.) 

Elongated, active polychsBts with broad, leaf -like dorsal and ventral 
cirri which do not cover the back; prostomium with 4 or 5 short ten- 
tacles and 2 or 4 eyes; peristomium with usually 4 long cirri on each 
side; proboscis with longitudinal rows of prominent papillae: about a 
dozen genera with numerous species. 

Key to the genera of Phyllodocidae here described : 

01 Four pairs of peristomial cirri present. 

&! Four tentacles 1. Phtllodoce 

6, Five tentacles 2. Eulaua 

o, Two pairs of peristomial cirri 3. Eteonk 

1. Phtllodoce Savigny. Body long, slender, and flattened, with 4 
tentacles on the prostomium, and often a pair of rudimentary parapodia 
on the peristomium together with the cirri: about 60 species, 7 in New 

P. gronlandica Oersted. Color green or yellowish with irregular 
brown markings; usual length 10 to 15 cm.: New Jersey to Greenland, 
from low-water mark to 50 fathoms. 

P. catenula Verrill. Color pale green with longitudinal rows of 
brown spots on the back; prostomium longer than broad, with a pair of 
large brown eyes; tentacles short; peristomial cirri very long; length 
up to 7 cm.; width 1.5 mm.: Rhode Island to Bay of Fundy and north- 
wards, from low-water mark to 50 fathoms; common. 

2. Eulalia Oersted. Body slender and flattened, with 5 tentacles 
on the prostomium and 4 pairs of peristomial cirri: 7 species in New 

E. pistacia Verrill. Color bright yellowish-green; body slender; 
tentacles short; peristomial cirri long; length 4 cm.; width 1.5 mm.: 
Long Island Sound to Maine, in 4 to 12 fathoms, among hydroids, etc. 

3. Eteohe Oersted. Body slender, flattened with 4 tentacles and 

2 pairs of cirri on somite 2 which is fused with the peristomium: 4 
species in New England. 

E. alba Webster. Color white; length 40 mm.: on mussel beds; 
New Jersey to Cape Cod. 

Family 3. SYLLIDAE. (Fig. 452, B.) 

Elongated worms, mostly under an inch in length, with usually very 
long slender dorsal cirri, which may be flattened; prostomium with 3 



tentacles, 2 palps, and 4 eyes; peristomium with 2 cirri on each aide; 
reproduction normally by asexual budding: numerous species; abundant 
in clean, shallow water among hydroids, mussels, and tunicates. 
Key to the genera of Syllidae here described: 

a. Palps prominent ; ventral cirri present ; tentacles and cirri segmented. 

1. Syllis 
a. Palps rudimentary; ventral cirri absent; tentacles and cirri filiform. 


1. Syxjib Savigny. Tentacles and cirri segmented, the latter often 
terminally dilated; palps large; new individuals formed by terminal, 
and in case of Syllis ramosa, lateral budding; numerous 

species, 2 in the Woods Hole region. 

S. pallida Verrill. Body slender, tapering at both 
ends, 15 to 25 mm. long; color white: 
Long Island Sound to Bay of Fundy; in 
mud, sand, and on shells, from low-water 
mark to 30 fathoms. 

2. Avtolttus* Grube. Tentacles and 
cirri not segmented; palps rudimentary 
or absent; ventral cirri wanting; the 
young individual acquires a head before 
separating from the parent, and a num- 
ber may be present in a row; males and 
females differ in appearance: numerous 
species, 6 in the Woods Hole region. 

A. cornutua A. Agassis. Length 15 
mm. ; color pinkish ; full-grown male hav- 
ing 30 segments, female 40 to 50 seg- ng ^ 4&g 
mente: New Jersey to Bay of Fundy, ^ m _ AMM9t J „ oHmm 
from low-water mark to 15 fathoms; ttf^MffiSH ?$& 

A. vaxians Verrill (Fig. 457). Length 
15 mm.; intestine with bright-red spots which can be seen through the 
body wall: North Carolina to Maine, often among hydroids. 

Family. 4. HE8IONTDAE. 

Body rather short and often cylindrical; parapodia usually nnira- 
mona and with long, jointed dorsal setae; 4 eyes, 2 or 3 tentacles, and 
2 palps on the prostomium; peristomium with long cirri: speciea not 

» Bw "AntolrtUB," by P. C, Henscb, Jour. Worpb., Vol. «, p. 2«9, 1»0. 



Podabks Ehlers. Six pairs of long cirri on the peristomium and 
first two somites: several species. 

P. obscnra Verrill (Fig. 458). Color variable, usually brown or 
blackish, sometimes with transverse bands; length up to 4 cm.; width, 
including setae, 3 mm.: Gulf of Mexico to Cape Cod; on eel grass and 
under stones; abundant. 

Family 5. NEBEIDAE. (Fig. 459.) 

Fig. 459 — Head of a 
nereld. 1, prostomlum ; 
2, tentacles ; 3, palp ; 4, 
periBtomial cirri; 5, 

Elongated polyenes with 2 small tentacles, 2 palps, 4 eyes on 
the prostomium, and 4 pairs of peristomial cirri; proboscis with 2 

large jaws; parapodia well developed: several 

Nebeis L. Clam worms. Body elongate and 
flattened; in some species during the sexual 
period the hinder part (epitoke) of the animal 
with the sexual products differs from the forward 
part (atoke) in appearance and the animal is 
called a heteronereis : numerous species, 7 in the 
Woods Hole region. 
N. virens Sars. Large worms, flesh-colored, with a 
greenish sheen; jaws black; dorsal division of notopo- 
dium foliaceous; length up to 30 cm. or more; width 
1 cm.: common from Long Island Sound to Labrador, 
buried in the sand near the low- water mark; breeding 
season spring; Europe. 

N. limbata Ehlers (Fig. 460). Color brownish; 
jaws light amber-colored; dorsal division of notopodium 
foliaceous; length up to 15 cm.: Maine to South 
Carolina; in the sand from high-water mark to 5 fath- 
oms; abundant south of Cape Cod. 

N. pelagica L. Color reddish-brown; body widest 
in the middle; dorsal division of notopodium conical; 
length up to 20 cm.; width 8 mm.: Virginia to Green- 
land; on hard bottoms from low-water mark to 100 
fathoms; Europe; North Pacific. 

N. limnicola* Johnston. Color reddish-brown; length 47 mm.; 
width 3 mm.; eyes large and conspicuous: in fine sand in Lake Merced 
(fresh water) near San Francisco. 

Fig. 460 

Hs limbata— 


anterior end 

with extended 



1, proboscis 

2, jaws. 

• See "Freeh-water Nereids from the Pacific Coast and Hawaii," etc., by H, P, 
Johnston, Mark Ann. YqL, p. 205, 1003, 



Elongated polychaats with flattened dorsal and ventral surfaces, 
giving a quadrangular cross section; prostomium with 4 small tentacles, 
the ventral pair being modified palps; peristomium with parapodia bear- 
ing setae and a pair of short cirri; proboscis very large with long fleshy 
projections in front; the two lobes of the parapodia widely separate: 
few genera and species. 

Nepethts Cuvier (Fig. 452, C). Characters as given above: nu- 
merous species, 4 in the Woods Hole region. 

K. indfla Malmgren (N. ingens Stimpson). Proboscis with large 
dorsal and small ventral papillae; length 13 cm.; color white: Long 
Island Sound to Bay of Fundy and northwards, from below low-water 
mark to 60 fathoms, on muddy bottoms; Europe; common. 

K. bncera Ehlers (N. picta Ehl.). Body slender with over 100 seg- 
ments; setae very long, often exceeding in length the diameter of the 
body; forward tentacles longer than half the width of head; length 20 
cm.; width 5 mm.: South Carolina to Massachusetts Bay, in shallow 
water in sand, and among rocks. 

Family 7. LEODICIDAE. 

Elongated polychets with a complicated jaw apparatus in the pro- 
boscis; the cirri of the anterior parapodia form branching gills in most 
species; prostomium either with 3 to 5 tentacles and a pair of palps or 
without cephalic appendages; usually a permanent parchment-like tube 
formed: about 30 genera with several hundred species. 

Key to the genera of Leodicidae here described: 

<h Gills present. 
b t Peristomium consisting of 1 segment and with cirri ; gills branched. 

2. Diopatba 
6, Peristomium consisting of 2 segments. 

4 Gills branched 1. Leodice 

c, Gills simple 3. Marphysa 

a, Gills absent. 
6t Head without appendages. 

Ox Eyes absent 4. LUKBHtzncREis 

0t Four eyes in a transverse row 5. Arabella 

6, Head with appendages .6. Staubonebeis 

1. LsODZOX Savigny (Eunice Cuvier) (Fig. 452, D). Body elongate 
with numerous segments; peristomium consists of 2 segments with 1 pair 
of cirri ; 5 tentacles and 2 large palps present ; gills begin usually on sixth 
segment: species very numerous, 2 in the Woods Hole region, in rather 
deep water. To this genus belong the largest known poh"*J»*»ts, the larg- 
est species having a length of 1 m. and more. 


L. fneata* Ehlera. Atlantic palolo worm (Fig. 461). Length np to 
35 cm., the atokal portion being about two-thirds the whole; color 
brownish or yellowish: West Indies and Gulf of Mexico; living in coral 
rock and swarming within 3 days of the full of the July moon. 

2. DioriTHA Ehlers. Peristomiam with 

1 pair of cirri; 5 tentacles in a transverse 
curved line and 2 small palps present; gills 
beginning several segments back from the 
head: many species, 1 in New England. 

D. cuprea (Base) (Fig. 462). Large 
worms up to 30 cm. long and 10 mm. wide 
which live in parchment-like tubes extending 

2 or 3 feet in the sand; the upper 2 or 3 inches 
of the tube projecting into the water and 
thickly covered with shells, etc. : common in 
shallow water and between tide lines; from 
South Carolina to Cape Cod. 

3. Mabphyba Quatrefages. Peristomium 
consists of 2 segments, and is without cirri; 
5 tentacles in a transverse row, 2 small palps 

and 2 eyes present; gills begin about the 20th segment but are variable 
in this respect : 1 species at Woods Hole. 

H. leidyi Qnatr. {M, smguinea Leidy) (Fig. 463). Length 20 cm.; 
eolor yellowish or brownish-red; tubes not so perfect as those of pre- 
ceding worms: under stones and in the sand in shallow water; from 
North Carolina to Vineyard Sound. | 

4. LincBsivzxxn Blainville (Lum- 
briconereig Ehlers) . Head conical, without 
appendages or eyes ; peristomium consist- 
ing of 2 segments; dorsal cirri flat, and 
parapodia small: many species, 5 at 
Woods Hole. 

L. tennis (Yerrill). Body filiform 
up to 30 cm. long, with the diameter of 
a coarse thread, bright red in color: Vir- 
ginia to Massachusetts; burrowing 

mud and under stones. . .„ -- r 

r . „ i „. ., rtorend (Verrtu) 

6. Ajlabxlla Grube.. Similar to 
Lumbrinereis but with usually 4 eyes in a transverse row on the 
prostomium: several species, 2 in the Woods Hole region. 

Fig. 461— Leodlot fncata 

B, bead end. 1, tentacles; 
2, palp ; 3, peristomium ; 4. 
perlBtomlal cirri ; S, gills. 

Tig. 463 PlS. 463 

Fig. 463 — Diopotra cupr 

tral view of anterior end ( 

1 tentacles : 2. perlBtomlal clmia. 
pig. 46B— Jrorenyro Wdirf— ante- 
rior end (VerrtU). 


A. opalina (Verrill) (Fig. 464). Body cylindrical, largest 
middle, reddish or yellowish in color, up to 40 cm. long, and 3 mm. 
North Carolina to Maine; borrowing in muddy sand; common; 

6. SlAtTEoraxxiB Verrill. Prostomiom small and 
qnadrangolar with 2 tentacles and 2 palps; gills not 
present, the dorsal cirri being long and slender: several 
species, 1 in the Woods Hole region. 

8. pallidas Verr. Two pairs of eyes present; color 
pale yellow; length 5 cm.; width .7 nun.: Virginia to Capa 
Cod; in the sand at low-water mark. 

Family 8. GLYCEMDAE. 


Elongated cylindrical worms with usually small para- *(verrm)° fl 
podia, and an annulatod prostominm which bears 4 small 
tentacles and 2 rudimentary palps; proboscis very large and long, with 
4 teeth; special retractile gills present either on the body wall or the 
parapodia: about 5 genera; the worms live in cylindrical passages in the 
sand, which they make with the proboscis. 

Key to the genera of Glyceridae here described: 

n, Parapodia of same structure throughout 1. Glyceka 

Hi Parapodia with 1 lobe on anterior third of body and 2 

lobes on posterior portions 2. Goniada 

1. GlTCtta Savigny. Parapodia of the same struc- 
ture throughout: several species, 3 at Woods Hole. 

G. dibrsjichiata Ehlers (Fig. 465). Length 20 cm.; 
proetomium sharp and conical; both dorsal and ventral 
gills large, simple, and flat : from North 
Carolina to Bay of Fnndy and north- 
wards; in shallow water, burrowing 
very rapidly in sand and mud; often 
very common. 

G. americana Leidy (Fig. 466). 
Length 20 cm. ; width 4 mm.; dorsal gills 
branched; ventral gills absent: from 
South Carolina to Cape Cod; in shallow 
water; not so common as G. dibranchiata. 

2. GovUDA Audouin and Edwards. Parapodia on the first third 
of the body with a single lobe, on hinder part with 2 lobes: several 
species, 2 in New England. 

O. maculata Oersted. Body slender with about 194 segments; the 
first 40 parapodia 1-lobed, the following 2-lobed; 2 principal teeth; 

Fig. 4 

Fig. 46B ■ -Glycera 
Mbrtmchiaia — an- 
terior end (Verrill). 
1, pro b torn I urn. 

anterior end 
with proboscis 




length 10 cm. : Maine coast, from low-water mark to 30 fathoms, in rock 
and sand; Europe. 

Family 9. ABICIIDAE. 

Usually cylindrical worms with short knob-like tentacles and palps, 
or none at all, and with filiform gills which are more or less dorsal in 
position: the worm forms a tube by cementing the sand around its 
burrow, the position of which can be detected by a mound at the opening; 
species not numerous. 

1. Aezoia Savigny. Body short and composed of many small seg- 
ments; tentacles and peristomial cirri absent; ventral cirri fimbriate or 
pectinate: several species, 1 at Woods Hole. 

A. ornata Verrill. Body stout and somewhat flattened; gills flat- 
tened, lanceolate, and begin on the sixth segment; length up to 26 cm.; 
width 7 mm.: North Carolina to Cape Cod; in shallow water. 

2. SooLOPLOS Blainville. Body usually elongate and fragile, with- 
out tentacles or peristomial cirri; proboscis lobulate: several species, 
3 at Woods Hole. 

8. robustua (Verrill). Large worms 30 cm. long and 7 mm. wide, 
with an acute head and small anterior parapodia; elongate gills begin 
on segment 26; proboscis divided into about 18 long slender lobes; color 
yellowish-brown : in shallow water, from North Carolina to Cape Cod. 

8. fragilis (Verr.). Body 12 cm. long, 3 mm. wide; head acute, with 
a 6-lobed proboscis; the gills begin to appear in segment 16; color yel- 
lowish: between tide lines; from North Carolina to Maine. 

Suborder 2. SPIONIFORMIA. 

Neither tentacles nor palps present; 1 pair of long peristomial cirri 
usually present; parapodia small, the dorsal cirri often large and form- 
ing gills; proboscis without jaws; worms burrowing or tubicolous: 2 

Family 1. SPIONIDAE. 

Small burrowing worms with a pair of long peristomial cirri which 
usually curve over the back; dorsal cirri acting as gills; proboscis pres- 
ent, but unarmed; body divided into 2 regions: in tubes in the sand, or 
burrowing in wood or shells; species not numerous. 

Key to the genera of Spionidae here described. 

Oi Segment 5 not enlarged. 

b t Gills on hinder half of body 1. Spio 

ft. Gills absent on hinder half of body 2. Laonigb 

a, Fifth segment different from the others 8. Poltdori 


1. 8*xo Fabricius. Segments alike throughout; head with a promi- 
nent median lobe which may be truncated or divided in front; 4 eyes; 
gills on all the segments: several species, 2 at Woods Hole. 

8. setosa Verrill (Fig. 467). Body long, flattened above and rounded 
below; parapodia 2-lobed; color green; gills and cirri red; length 8 cm.; 
width 2.5 mm. : Long Island and Vineyard Sounds; at low- 
water mark. 

2. Laohzob Mahngren. Segments alike throughout; 
prostomium with 2 or 4 eyes, very broad in front; gills 
absent from hinder half at least of body : several species, 
2 at Woods Hole. j^ g 437 

L. (Scolecolepis Blainville) viridig (Verrill). Body ^^iewV 

flattened; color olive green or brownish; length 10 cm.; "verrfif)^ 

breadth 3 mm.: Long Island and Vineyard Sounds; near ^^J^T** 1 
low-water mark; often common. 

3. Poltdoea Bosc. Fifth segment different from the others, being 
much longer and with characteristic setae: many species, 7 at Woods 

P. concharum Verrill. Body long and slender, being 14 cm. long 
and 1.5 mm. wide, with 200 segments; color grayish or yellowish: very 
common from Cape Cod to Nova Scotia; in 10 to 100 fathoms, often 
burrowing in shells. 

Family 2. CR32TOPTEBIDAE. 

Worms living in U-shaped parchment-like tubes up to 50 cm. long, 
buried in the sand and mud; 3 distinct regions in the body; no tentacles 
or palps present and but 1 pair of peristomial cirri which tend to project 
backwards; proboscis wanting: few genera and species. 

Ohjetoptebub Cuvier. Parapodia simple, consisting of large, ex- 
panded notopodia in the anterior body region, but may be biramous in 
the other two regions: 15 species, 1 at Woods Hole. 

0. pergamentaceus Cuv. Body short and stout; anterior region 
much flattened; middle region composed of 1 segment with large wing- 
like parapodia and 4 swollen segments; body walls very {hin, intestine 
and genital products showing through; highly phosphorescent; length 
15 cm.: North Carolina to Cape Cod; Europe. 


Prostomium a prominent lobe with or without tentacular filaments 
which represent the tentacles and without palps; peristomium with or 
without cirri; parapodia weak, without ventral cirri, the dorsal cirri 


sometimes acting as gills on the anterior or all segments; no proboscis or 
jaws present: 4 families; worms burrowing or tubieolous. 
Key to the families of Terebellifomia: 

«, Head without appendages 1. Obbatulidax 

a. Head with long tentacular filaments, 
fi, Tentacular filaments very long. 

o, No setae on head 2. Tkbxbeliidu 

c, A handle of setae on each side of head 3. AlfPHARBTIDAX 

bi Tentacular filaments short 4. Amphiotenidab 


Small and medium-sized cylindrical worms which are usually found 
in burrows or under stones; head distinct but without appendages or 
proboscis; parapodia rudimentary, but dorsal cirri very long and fila- 
mentous and acting as gills: sev- 
eral genera. 

Oieratuxus Lamarck. Head 
conical; cirri very long and slen- 
der, a pair of them being present 
on almost every segment; a trans- 
verse row of long branchial fila- 
ments on one of the anterior seg- 
ments: many species, 4 ut Woods 

0. drratua (0. F. Miller). 
Head consists of a proatominm 
and a peristomial segment; a row 
of eyes on the prostomium; length 
S cm.; width 4 mm.: coast of 

Fig. *68— CirratiilM grandii (Verrlll). ,, . . . .__ _, 

l, dorsal cirri. Maine; in tabes under stones; 


0. grandis Yerrill (Fig. 468). No eyes present; first 3 segments 

without cirri; color yellowish-green; length 15 cm.; width 6 mm.; length 

of longest cirri 6 to 10 cm.: Virginia to Cape God; in sand and gravel, 

in shallow water; common. 

Family 2. T BBEBEL LI P A E. 

Long and often thick worms living in burrows or tubes; head with 
a prominent horseshoe-shaped preoral lobe whose anterior margin is 
reflexed, behind which is a transverse ridge bearing large numbers of 
long tentacular filaments which act as gills; behind these are usually 
1 to 3 pairs of branching gills belonging to the anterior segments ; para- 
podia reduced; both capilliform and hooked setae: numerous species. 

VOttCBMTA 295 

Key to the genera of Terebellidae here described : 
<H Worms not filamentous ; branching gills present. 
6, Three pairs of branching gills present. 

Oi Capilliform setae only on anterior somites 1. Amphitbitb 

c, Capilliform setae also on posterior somites 4. LXPftU 

6, Two pairs ot branching gills. 

c, Capilliform setae begin on segment 4 2. Pista 

o, Capilliform tetae begin on segment 3 6. TffiXEPUa 

6, Bat 1 gill, which has 4 branches 3. TnmujDM 

u, Worms filamentous and blood red ; no branching gills. 

6, Parapodia simple 6. Poltcibbus 

6, Parapodia elongated and branched 7. Bkoplobunchus 

1. Axfxttbitx 0. F. Miiller. Body cylindrical, thickest towards 
the forward end ; 3 pairs of branching gills ; setae begin on the 4th seg- 
ment and confined to anterior part of body; no eyes: many species, 4 
in the Woods Hole region. 

A. ornate (Leidy) (Fig. 469). Color pinkish; length np to 30 em., 
with about 40 setigerous segments; tentacular filaments very long, nu- 
merous, and contractile: North Carolina to 
Cape Cod, at low- water mark; common, living 
in firm tubes which are sometimes cast np on 
the beach. 

A. brnnnea (Stimpson). Color dark red- 
dish-brown; segments about 100, 25 of which 
have setae; each gill with 7 to 12 branches; 
length np to 18 cm.: north of Cape Cod at 
low-water mark, in deeper water towards the 

2. Pibta Malmgren. Two pairs of branch- 
ing gills; setae begin on the 4th segment and 
extend to the 20th; no eyes; first 3 somites 
■with large ventral and lateral wings : 3 species 

in the Woods Hole region. AmpMr i t V&% rv errt ,i>. 

P. palmate (VerriH). Body rather slen- *• tantacujsr^ianienti 
der, with 17 setigerous segments; color reddish- 
brown; length 7 cm.; width 2 mm.; animal constructs tubes of bits of 
shell, etc.: Long Island and Vineyard Sounds. 

3. TSUBZLLTDEI Sars. Two pairs of gills present which are 
large and form 4 wide, comb-like branches on a single peduncle; ten- 
tacular filaments numerous (over 100) : 1 species in the Woods Hole 

T. Itrotml Sars. Body with about 60 segments and reddish in color; 
length 7 cm.; width 5 mm.: Vineyard Sound to Bay of Fundy; in 10 
to 250 fathoms; Europe. 


4. IittPBflCA Malmgren. Three pairs of branching gills; setae begin 
on 4th segment and extend the length of the body: several species, 1 in 
the Woods Hole region. 

L. rubra Verrill. Body elongate, swollen anteriorly; color bright 
red; length 5 cm.; width 3 mm.: North Carolina to Vineyard Sound; 
in tubes on shells, etc., below low-water mark. 

5. Thelefto Leuckart. Two pairs of branching gills; setae begin 
on the 3rd segment and continue nearly or quite to the hinder end ; eyes 
numerous: 1 species in the Woods Hole region. 

T. cindnnatus (Fabricius). Setae extend almost to the hinder end 
of the body; eyes present; length up to 12 cm.; color yellowish or red- 
dish: coast of Maine to Vineyard Sound; in tubes often covered with 
shells; Europe. 

6. Polyotbeub Grube. Blood worms. Very long, slender worms 
with bright-red blood ; no branching gills : several species, 2 in the Woods 
Hole region. 

P. eximius (Leidy). Body bright red with about 100 segments, of 
which 25 bear setae: North Carolina to Cape Cod; in sand and mud in 
shallow water; very common. 

P. phosphorous Verrill. Brilliantly phosphorescent worms when 
disturbed; length 8 cm.; first 24 segments bear setae: Long Island 
Sound to Bay of Fundy. 

7. Ehoplob&anohto Verrill. Blood worms. Body flattened; setae 
extending to the hinder end of the body; with branched parapodia in 
the middle division : 1 species. 

E. sanguineus (Verr.). Body very long and slender; branched para- 
podia begin on segment 12; color bright red; length 35 cm.; width 7 
mm.: Virginia to Gulf of St. Lawrence; common at low-water mark; in 
mud and sand. 


Similar to the previous family; a bundle of setae present on each 
side of the head in front of the gills; tentacular filaments small and not 
numerous; no branched gills, but 4 pairs of filamentous ones present: 
several genera. 

Amtkasste Malmgren. Tentacular filaments few in number; 
gills on 3rd and 4th segments: numerous species, 2 in Woods Hole 

A. setosa Verrill. Body thick anteriorly, tapering backwards; 40 
tentacular filaments; color light green or red; length 20 mm.; width 3 
mm.: Long Island and Vineyard Sounds; in rough tubes in shallow 



Small worms which form tabes of sand open at both ends which 
can be carried about by their occupants; the prostomium bears short 
filamentous tentacles which are protected by long yellow setae; binder 
end of the worm without parapodia and folded ou the forward part: 
several genera and few species. 

Pxctixabu Halmgren. Characters as given above : several species, 
2 in the Woods Hole region. 

P. gouldi (Verrill) (Kg. 470). Body flesh-color, mot- 
tled ; length 4 cm. ; width 7 mm. : North Carolina to Maine ; 
in shallow water. 


Head pointed and not distinctly set off, 
without tentacles or palps but with a pair of 
ciliated, retractile, tentacle-like organs; para- 
podia rudimentary, with sessile capilliform 
setae on the anterior and sessile hook-like ^ 

ones on the posterior segments; proboscis 
without jaws : 1 family. 

With the characters of the suborder: 
several genera. ^ 4i*-feummi» #mUi 

1. NoTOMABTtni Sara. Prostomium con- ^J™ 11 '- a. tbe worm ; B, in 
ieal, without eyes; body composed of 2 por- 
tions, a forward thicker part (thorax) consisting of about 12 biannn- 
lated segments, and a long hinder portion : several species, 3 in Woods 
Hole region. 

V. lnridus Verrill. Long, cylindrical worms, 15 cm. long, 2 mm. 
thick; color dark brown: Long Island Sound to Maine; at low-water 
mark in tubes in muddy sand. 

N. filiform!* Verr. Body filiform, 10 cm. long, 1 mm. thick; color 
pale red, often mottled with whitish : Long Island and Vineyard Sounds ; 
at low-water mark. 

2. Capitella Blainville. Large genital setae on 8th and 9th seg- 
ments; thorax consisting of 9 segments; only the middle portion of the 
body with setae: several species, 1 in Woods Hole region. 

0. gracilis (Verrill). Length 5 cm.; color red; head trian- 
gular: Cape Cod to Bay of Fundy; in tubes in the mud in shallow 



Head without appendages (except in the Chlorhcemidae) ; parapodia 

poorly developed or absent; proboscis present but unarmed: 6 families. 

Key to the families of Scoleciformia here described: 

Of Head without appendages. 
&i Segmentation equivalent ; body not made up of different regions. 

1. Ophetjidab 
6, Segmentation not equivalent ; body made up of 2 or 3 more or less dis- 
tinct regions. 

ojl Worms slender and without gills 2. Maldanidas 

c, Worms thick, with branching gills on the middle segments. .3. Abenicoijdae 
a% Head with appendages 4. Chlobhjemidae 

Family 1. OPHELIIDAE. 

Small burrowing worms which occur in shallow water; head with- 
out appendages but with a proboscis; parapodia rudimentary, the dorsal 
cirri of which are elongate and act as gills: about 6 genera. 

Axxotxtpaks Rathke. Head conical and acute; 
ventral side flattened: 1 species at Woods Hole. 

A. fimbriata Verrill (Fig. 471). Body elongate, being 
thickest in advance of the middle and tapering to both 
ends; color purplish; length 7.5 cm.; width 3 mm.: Vine- 
yard Sound .to Maine; in shallow water. 

Family 2. MALDANIDAE. 

Slender, cylindrical worms which live in sand tubes; 
Fig. 471 head formed of the fused prostomium and peristomium 

m flmbriata and usually obliquely truncated by a cephalic plate and 

without appendages; parapodia rudimentary, with setae 
but without gills; hinder end funnel-shaped, usually with frilled edges: 
7 genera. 

Key to the genera of Maldanidae here described : 

Of Anus dorsal to caudal funnel. 1. Maldani 

a t Anus in center of caudal funnel. 

6i Anal funnel without cirri 2. Clymknblla 

0, Anal funnel with cirri 3. Nioomachs 

1. Maxdave Grube. Body elongate, truncated at both ends, most 
of the segments being biannulated; anus dorsal: numerous species, 
several in the Woods Hole region. 

M. urceolata (Leidy) (M. elongata Verrill). Body elongate with 19 
setigerous segments, the middle ones being much elongated ; color reddish- 
brown; length 30 cm.; width 5 mm.: in sandy mud at low-water mark; 
North Carolina to Cape Cod. 



2. Olyxevslla Verrill. Body with 18 or more setigerous segments 
and with obliquely truncated head : several species, 2 in the Woods Hole 

0. torquata (Leidy) (Fig. 472). Body with 
a membranous collar arising near the middle of 
the 4th setigerous segment; 22 segments, 18 with 
setae; eolor reddish; length 10 cm.: North Caro- 
lina to Bay of Fundy; in sand from low-water 
mark to 60 fathoms. 

3. Kiooxachx Malmgren. Funnel-shaped ter- 
minal segment with marginal cirri; head without 
truncating plate; prostomium sharply bent down- 
wards: several species. 

N. lumbricalis (Fabricius). Body slender and 
fragile, consisting of 26 segments; color pink; 
length 7 em.: Cape Cod and northwards; Europe. 

pig. 472 — Clymenella 
torquata (Leidy). 

A. entire worm 

B, hinder end. 


Fig. 473 





Family 3. ARENICOL1DAE. 

Elongated worms which burrow deep in the sand; 
head without appendages, with an unarmed proboscis; 
peristomium with a pair of lithocysts; parapodia rudi- 
mentary, with branching gills above them in the middle 
of the body: 1 genus. 

Abevioola Lamarck. Anterior end blunt, the pro- 
stomium and peristomium being fused together; body 
cylindrical, thickest at the forward end: few species, 2 
in the Woods Hole region. 

A. marina (L.) (Fig. 473). Segmentation indistinct, 
the skin being annulated; about 21 setigerous segments 
present, of which 8 compose the anterior and 13 the 
middle region, but only 4 dissepiments and 6 pairs of 
nephridia; length up to 20 cm.; diameter 8 mm.: Long 
Island Sound northwards; in deep burrows in the sand; 
rare south of Cape Cod; Europe. 

A. cristata Stimpson. Head very small; middle 
branchiate region with 11 pairs of gills; color greenish- 
yellow; length 35 cm. or more: Florida to Cape Cod. 

Family 4. CHLOBHJEMIDAE. (Fig. 452, F.) 

Rather small worms which live in burrows and under stones; body 
not divided into regions; whole head retractile and with a circle of 3 to 


20 pairs of green, short tentacular filaments which act as gills; palps 
large; proboscis unarmed; blood green; setae of the anterior segments 
often very long and projecting directly forwards: 6 genera. 

1. Thopbohia Milne-Edwards. Anterior setae pro- 
longed, enclosing the head: 2 species in the Woods Hole 

T. aSnis (Leidy) (Fig. 474). Body slender and 
elongate; 8 tentacular filaments on head, which are blunt 
and of unequal length; length 6 cm.; width 3.5 mm.: 
Vineyard Sound and New Jersey; in 20 fathoms. 



Troj>honia Prostomium more or less hidden by the forward 

*(VerriU) I>d extension of the peristominm which usually forma a 
projecting collar; tentacles rudimentary or very small; 
palps very large, forming the branchial crown; proboscis present; body 
consisting of 2 regions, a thorax of about 9 segments, and an abdomen; 
worms tubicolous: 4 families. 

Key to the families of Sabellifomia here described : 

o, Tubes membranous. 1. SABELUDAE 

u, Tubes calcareous. 2. Skkpuxidaz 

Family 1. 8ABELLIDAE. 

Worms which live in membranous tubes in mud and sand; arising 
from the prostomium is a pair of large semi-circular feathered gills rep- 
resenting the palps, which may be surrounded by a collar formed of the 
peristomium ; tentacles rudimentary or bidden; parapodia very rudi- 
mentary: many genera. 

Key to the genera of Sabellidae here described : 
a, Peristomial collar present. 

b. Collar lobes separated dorsally T. Sabcula 

0, Collar lobes meeting dorsally 2. Potaiulla 

a, Collar absent. 

b, Worms live in gelatinous masses ; no eyes 3. Htxioola 

0| Worms live in distinct tubes ; eyes present. 

o, Worms In fresh water 4. Makatt/KBU 

c, Worms marine S. Fabrici* 

1. Saheit.s Malmgren. Gill filaments long and slender; peristo- 
mium raised and reflexed to form a collar around the gills which is 
notched dorsally: many species. 

* Bee 'Tnblcoloue Annelida of tbe Tribes Sabellldes and Berpntldes from the 
Pacific Ocean," by K. J. Blub, Harrlman Alaska Exp., Vol. 13, 1910. 



S. microphthalma Verrill. Body short, composed of about 60 seg- 
ments; anterior region composed of 8 setigerous segments; gill filaments 
with minute eye spots; color greenish-yellow; length 5 cm.; diameter 

3 mm : North Carolina to Cape Cod ; at low- water mark, often incrusted 
on oyster shells, etc. 

2. PoTAmx* Malmgren. About 12 to 30 gill filaments on each 
side, some of which have eyes at the base; 

peristomial collar without a dorsal notch: 
several species. 

P. ocultfera (Leidy) (P. reniformin 
Malm.). Length 8 em.; color greenish or 
reddish-brown: New Jersey to Bay of 
Fundy; on shells in tide pools; Europe. 

3. Mtxicola Koch. Body thick ; hinder 
region with numerous hooks in transverse 
rows; gill filaments united by a mem- 
branous web; without eyes on head; eye 
spots on terminal segment; 2 small ten- 
tacles: worms live in gelatinous masses 
attached to shells, etc., in which each worm 
has a separate tube; several species. 

M. steenrtrupi (Krbyer). Body thick, 
with about 60 segments, of which 8 belong 
to tbe anterior body region; color pink; 
length 6 cm.; width 5 mm.: north of Cape 
Cod; Europe. 

1. HaVATrasu Leidy. About 36 gill 
filaments with eyes at their bases; body 
composed of but few segments; 1 species; 
in fresh water. 

It specie** Leidy (Fig. 475). Body 

4 mm. long and consisting of 12 segments, 
and yellowish-brown in color: in tubes on 
atones in Schuylkill River, Philadelphia, also in Egg Harbor River, New 
Jersey, associated with Urnatelia gradlit. 

5. Fabbioia Blainville. Bnt few gill filaments or tentacles; body 
composed of bnt few segments: few species, 1 in the Woods Hole 

F. lsidyi VerrilL Body 3 mm. long and 2 mm. wide, consisting 
of 13 segments and yellowish-brown in color; 6 gill filaments: Long 
Island Sound to Bay of Fundy; in slender tubes, at and below low- 
water nark. 

MM ipeciota (Lddr), 



Family 2. SERPULIDAE. (Fig. 476.) 

Worms which live in calcareous tabes; arising from the prostominm 
are a pair of large semicircular feathered gills which represent the 
palps; an operculum usually present, composed of the dorsal gill- fila- 
ments; just beneath the gill filaments is the 
collar, a paired membrane employed in smoothing 
the inside of the shell: numerous genera and 

Key to the genera of SerpuUdae here described : 

Ox Tubes incrusted on shells, etc 1. Hydroides 

a, Tubes minute, spiral, usually on seaweed or shells. 

2. Sfibobbis 
a, Tubes intertwining 3. Filogbana 





Fig. 476— <A serpuUd 
rojecting from its 

1. Hydboxdes Gunnerus. Small worms living 

u Hi9f mb v rtd « e 2Sju- in long contorted tubes incrusted on shells, etc.; 

■al History). 1, gills; ° ' ' 

*' ^fSK?' 3 ' wd " funnel-shaped operculum present: several species, 

1 in Woods Hole region. 

H. hexagonus Bosc (E. dianthus Yerrill) (Fig. 477). Color of gills 
variable, oftenest a purplish-brown; length 75 mm.; diameter 3 mm.: 
Florida to Cape Cod; very common. 

2. Sfibobbis Daudin. A small worm living 
in a tube coiled usually in a flat spiral, which is 
incrusted on seaweeds, etc.; operculum present: 
many species, 6 in the Woods Hole region. 

S. spirorbis (L.) (S. boreaUs Daudin). Coiled 
tube 3 mm. across; length of animal 3 mm.; 9 
gill filaments present; color of gills greenish- 
white: Long Island Sound to Bay of Fundy and 

8. FrxooBAJTA Oken. Small worms living in slender white tubes 
which intertwine, forming masses 7 cm. high; 8 gill filaments present: 
1 species in Woods Hole region. 

F. implexa Berkeley. Body compressed, 4 mm. long; tubes very 
thin; color purple or pink: Maine to Vineyard Sound; Europe. 


Peristomium very much enlarged and forming a setigerous bilobed 
hood enclosing the prostomium, which bears a pair of tentacles and a 
pair of palps; the latter are fused with the ventral edges of the peristo- 
mium and project in the form of numerous gill filaments from the hood ; 
body composed of 2 regions, a thorax and a long tail-like abdomen which 
has no parapodia and folds back on the thorax : 1 family and few species. 

Pig. 477 

idea hove 

(Hargltt) on a shell. 

Hydroides hexagonus 



With the characters of the suborder: 3 genera. 

BajmLAjtta Lamarck. With the characters of the suborder: sev- 
eral species, 1 at Woods Hole. 

S. vulgaris Verrill. Color yellowish or reddish; length 3 em.; width 
2.5 mm.: North Carolina to Cape Cod; from low-water mark to 10 
fathoms; common in tubes of sand, also on shells. 

Order 2. OLXGOOHiETA.* 

Mostly fresh-water or terrestrial, 
hermaphroditic annelids which are with- 
out parapodia and cephalic appendages 
(Fig. 478). The setae are few in num- 
ber and project from pits in the body 
wall; in the Disco drilidae and Anachteta 
they are wanting. Some oligochnts have 
external gills (a few naids and tubiflcids). 
The head is small and consists of the 
prostomium, which is a small projection 
in front of the mouth, and the peristo- 
mium, which contains the mouth and 
often appears dorsally like the first somite 
of the trunk, but differs from the somites 
in that it has no setae. 

Paired ovaries and testes are pres- 
ent (Fig. 479) ; a number of large 
sperm sacs or vesiouUe seminales act as 
reservoirs of the sperm, in which the 
sperm ripens as it comes from the testes, 
and one or more pairs of pockets called 
the receptacula seminis or spermathecae 
receive the sperm of another animal dur- 
ing the act of pairing. The eggs and sperm are extruded into a capsule 
called the cocoon which is secreted by a thickened portion of the integu- 
ment called the clitellum. Development is direct, the young animal being 
born with the form of the parent; of the numerous eggs in a cocoon only 
a few, sometimes only one, batch out. Many oligochnts reproduce asex- 
ually, by transverse division, and the regenerative powers of all are great. 

• Be* "A Monograph of tbe Order Ollgorfuet*," by F. Beddard, 189S. "Notes on 
Species of North American Ollgocbata." by F. Smith, Ball. ill. St Lab.. Vol. 4, p. SSS, 
ISM. "Note* on Species of N. A. OUgoduata, II." \>j Mine, same jour., ToL 4, p. 

mouth ; it, opeclne* of tbe a 
matbecae ; 4, openings 
ducts ; S, openings of the sperm 
ducts ; 0, clitellum. Fig. 419 — 

legs of tbe o 

organs with 
id tbe rlght- 
-„ nd the left- 
hand female organs removed (Gal- 
i — ij) 1, prostomium ; 2, brain: 
_, _iontb ; 4, ventral nerve chord; 
0, spermathecae ; 6, nephridium; 
7. testis: 8, clitellum; 9, sperm 
duct; 10. ovarj- ; 11. sperm sac; 

12, oviduct; 13, ansae. 

tbe digestive 
band «-*"- ' 


Oligochffits are poorly provided with special sense organs. Pig- 
ment eyes are present in certain naids; tactile cells and processes may 
be present but tentacles never are. The forward part of the body of 
earthworms is especially sensitive to light and other stimuli. 

The terrestrial oligochffits are the earthworms. These familiar ani- 
mals are often of large size, the largest being six feet in length, and 
are found in temperate and tropical countries in all parts of the world. 
They are nocturnal animals which live in burrows in the soil and feed 
on decaying vegetation and the organic particles in the soil, which they 
pass in large quantities through the intestine. Darwin has estimated 
that an acre of ordinary ground will have about 63,000 earthworms 
which bring many tons of earth to the surface from a foot or two 
beneath. They are thus important agents in renewing the surface soil. 

The aquatic oligochffits live mostly at the bottom of fresh-water 
streams and ponds, although a few live in the sea, often in tubes of 
mud or sand, and eat aquatic vegetation. The order contains over 1,200 
species and about 11 families. 

Key to the families of Oligochceta here described: 

d Worms microscopic 1. .ASolosoicatidae 

Os Worms not microscopic. 

o x Parasitic worms with terminal sucker 2. Disoodbujdae 

6, No sucker present. 

Oj Worms very long and filiform. 3. Haflotazidak 

o, Worms not so formed. 

d, Worms usually very small and slender and mostly aquatic. 
d Reproduction mostly by serial budding, animal chains being formed. 

5. Naidioae 
e, Such reproduction not present, or at least uncommon. 
f x Spermatheca far forward, usually opening in segment 4 or 5. 

/, Spermatheca farther back. 4 - Encitytmidab 

g x Setae usually more than 2 in a bundle and usually of more than 

one form 6. Tubificidae 

g t Setae paired and all of one form 7. Lumbucuudae 

d, Worms large and mostly terrestrial ; earthworms. 
€i Clitellum begins before segment 18 and contains the male pores. 
f x Male pores in hinder margin of clitellum or entirely behind it. 

8. Meoasooucidab 

/, Male pores in forward portion of clitellum 0. Geosoolecidab 

Aj Clitellum begins at or behind segment 18 ; male pores some distance 

in front of it 10. Lumbugidae 

896, 1805. "Notes on Species,'* etc., by same, same jour., Vol. 6, p. 441, 1900. "Notes 
on Species of N. A. OUgocheta, IV," by same, same jour., Vol. 5, p. 450, 1900. 
"OUgocheta," by W. Michaelsen, Das Tierreicb, 1900. "Researches in American 
OUgocheta," etc., by G. EHsen, Proc CaL Acad. Sd., 3d 8er., ZooL, Vol. 2, 1000. 
"Hirudlnea and OUgocheta Collected in the Great Lake Region/* by J. P. Moore, 
Bull. U. 8. Fish. Com., Vol. 25, p. 155, 1905. "Some Marine OUgocheta of New 
England," by J. P. Moore, Proc. A. N. S., Phila., 1905, p. 373. "Die Sasswasserfanna 
Dentschlands," Heft 13, "OUgocheta," by W. Mlchaelsen, 1909. "The Common 
Freshwater OUgocheta of the United States," by T. W. Galloway, Trans, Am. Mlc 
Soc., Vol. 30, p. 285, 1911. 


Family 1. J30LO80MATIDAE. 

Microscopic fresh-water worms usually with brown, red, or yellow 
oil globules in integument, giving them a spotted appearance; no dis- 
sepiments present; setae in 4 bundles in each segment, of 1 to 6 setae 
each ; clitellmn only on ventral aide on segments 
5 to 7; nervous system hypodermic; prostominm 
ciliated ventrally; the most primitive oligo- 
ehasta, reproducing by division: 1 genus. 

.£oloboma Ehrenberg. With the characters 
of the family: about 9 species, 5 in this 

A. qnaternirinm Ehr. (Fig. 480) {A. venu- 
stum Leidy). Head of same width as body; 
setae sharply bent, those of the same bundle of 

the same length; the worm encysts itself; spots mJ^L^ 
red; length 1 mm., with 7 to 10 segments: tc * n, ^Sr y I )' tnr " 1 

among algae. 

A. hemprlchi Ehr. Head broader than body; setae nearly straight; 
spots red or crimson; length 2 to 5 mm., with 4 to IS segments; among 

*^' Family 2. DIBCODBLLIDAE. 

Small parasitic oligoehtots which were formerly grouped with the 

Sintdinea, with a sucker at the hinder end of the body and without 

setae, which live on the gills or the outer surface of crayfish; mouth with 

a dorsal and a ventral chitinous jaw; anus dorsal; 2 pairs of nephridia; 

1 or 2 pairs testes; single median genital pore in sixth segment: several 


Key to the genera of Ditcodrittdae here described : 

a. One pair testes 1. BBAHCmOBDBXLA 

a. Two pain testes. 

6, No dorsal appendages 2. Bdbllodbilus 

ft, Dorsal appendages present 3. Ptkbodkilub 

1. BlASCKlOBDXLLA* Odier. Dorsal and ventral jaws similar; 1 
pair testes in fifth segment : 3 American species. 

B. pulcherrlma Moore. Body 6 mm. long and 1.3 mm. wide, very 
transparent forward and somewhat flattened; eighth and ninth seg- 
ments flattened, each with a pair of adhesive organs: North Carolina. 

B. lnstabilia Moore. Body 5.5 mm. long, 1.3 mm. wide; hinder 4 
(segments forming a flattened disc-shaped expansion which is almost as 
wide as long, anterior segment very contractile: eastern states. 

* Bee "On Some Leechlike Partaltei of American Criyflihn," by J. P. Moore, 
Pro*. Ac Nat Set, Phils., 1893, p. 416. "Note, on Branch lobdells," b T W. M. Small 
wood, BioL Boa, Vol. 11, p. 100, 1008. 

2. Bdellodbixtth Moore. Two pairs of testes and sperm duets: 2 

B. illumlnatus (Moore) (Fig. 481). Bodj 4 mm. long and .9 mm. 
wide, the head being composed of 4 segments, the trunk of 11, all being 
biannulated ; clitellum is the dorsum of segment 
6: often common on the gills of crayfish; co- 
coons also on the gills; eastern North America. 
B. philftdelphlcuf (Leidy). Head the 
broadest part of the body ; length 10 mm. : on 
the external (usually the ventral) surface of 
crayfish; eastern and central North America. 
S. Ptebodutlub Moore. Two pairs of testes and sperm ducts; long 
paired, dorsal appendages on certain of the body segments; 2 species. 

P. distlchns Moore (Fig. 482). 
Dorsal appendages not branched; 
length 1 mm.: on the external sur- 
face of the crayfish in western 
New York. 


Body very long and slender or 
filamentous; setae sigmoid, single 

or paired, in 4 rows; 2 pairs of ovaries; central blood vessel contractile: 
2 genera and 3 species. 

Hap lo taxi b HofTmeister. Clitellum on segments 11 
to 14; 2 pair male pores on segments 11 and 12: 2 species. 
H. gotdioides Hartmann (H. emissarius Forbes) (Fig. 
483). Dorsal setae absent on the hinder fonr-fifths of 
body; length 18 cm. and more; width .6 mm.; 375 seg- 
ments: in wet ground or in the water (Illinois; Phila- 

Family 4. ENCHYTRaHDAE* 

More or less slender worms 30 mm. or less in length 
which live in fresh water along the shore of the sea or in 
decaying or living plants; setae hair-like, in 4 bundles in 
each segment; clitellum when fully developed occupies 
segments 11 to 13; dorsal blood vessel arises near the clitellum; testes 
i in segments 11 and 12: about 13 genera and 170 species. 


Key to the genera of Enchytraidae here described: 
a, Setae straight, or nearly bo. 

6, All setae in a bundle of equal length 1. EiTCHYTKaus 

6, Setae not all of equal length, inner setae of each bundle smaller than 

outer 2. FbidehiOiA 

a, Setae sigmoid. 

6, Blood yellow or red ; testes massive 2. Luhbbicillub 

b. Blood usually colorless; testes subdivided 4. Mbsinchttkaus 

1. EvoKmatra Henle. Setae straight or nearly so, all those in a 
bundle of equal length (Fig. 484) ; blood colorless; large salivary glands 
present: 10 species. 

E. albidus Henle. Milk-white worms 25 mm. long and 1 mm. thick; 
setae nearly straight but hooked at inner end 2 to 6 in a bundle; num- 
ber of segments 53 to 69: New Jersey to Maine, along the seashore near 
high-water mark tinder decaying seaweed and stones, also inland near 
the shore; very common in Europe and America. 

E. BOcUlis Leidy. Body translucent and 20 mm. long; setae 5 to 7 
in a bundle; mouth triangular: in groups, in rotten stumps and logs. 

(SAbbw. F. Dent.). 

2, LimBBioiLLirs Oersted (Fig. 485). Setae sigmoid; testes mas- 
sive; blood yellow or red; no salivary glands; clitellum covers segments 
11 and 12: 15 species. 

L. agilla Moore. Transparent worms with pink or brown internal 
organs, 16 mm. long and .4 mm. thick: Maine to Vineyard Sound, along 
the seashore under seaweed near high-water mark. 

3. F&IDWOU. Michaelsen (Fig. 486). Setae straight, 2 to 6 in a 
bundle and not of equal length, the inner setae of a bundle being shorter 
than the outer; blood colorless; salivary glands present: 21 species, 6 
in this country. 

F. alba Moore. Length 22 nun.; number of segments 58; sper- 
matheca simple; salivary glands branched; setae long and slender: in 
wet moss and leaves in the woods. 

F. pans. Moore. Length 10 mm.; number of segments 46; sper- 
matbeca and salivary glands unbranehed; 4 setae in a bundle as far as 


segment 25, then 2; color opaline white: among damp leaves, in the 

F. agilis Smith. Length 30 mm.; number of segments 57 to 66; 
dorsal blood vessel begins at segment 19; salivary glands much branched: 
in the soil (Illinois). 

4. Mesevohttbjeto Eisen. Setae sigmoid; blood usually colorless; 

no salivary glands: 30 species. 

M. beumeri (Michaelsen). Length 

l2 30 mm. ; setae 3 to 5 in lateral bundles 

* 6 ' ^ * j 1f ' and 5 to 8 in ventral ones; clitellum 

. . ^ , - , „ 1 . r , on segments 11 to 13 : Philadelphia, 

in wet places; Europe. 

Fig. 487 — Diagram of anterior por- _ -.*.▼» -r^-™ * ** « 

tion of a nald (Walton). 1, prosto- FAMILY 5. NAIDIDAE.* 

mium ; 2, eye ; 3, brain ; 4, mouth : 
5, pharynx; 6, oesophagus; 7. blood 

vessel ; 8, testis : 9, ovary ; 10. hair- Small aquatic, transparent worms 

like setae; 11, forked setae; 12, In- ,_. ^ rt „ v ._ ' .. - A 

testine ; 13, clitellum. (Fig- 487) with 2 to 4 groups of setae 

on each segment, and often with a 
distinct head; ventral setae forked; testes and ovaries usually in seg- 
ments 5 to 7; the worms reproduce principally by transverse division, 
forming animal chains : 15 genera and 50 species, mostly in fresh water. 
Key to the genera of Naididae here described: 

at Hair-like setae present dorsally. 

&! Proetomium not tentacular. 

Ox Without retractile rear appendages 1. Nais 

©, Retractile rear appendages present 4. Dero 

6, Proetomium long and tentacular. 

Ox Dorsal setae begin on 5th or 6th segment 2. Sttlabia 

c, Dorsal setae begin on 2d segment 5. Pristxha 

a, Hair-like setae absent dorsally. 

&! No dorsal setae present .6. Chjbtogastkb 

b t Forked dorsal setae present 3. Pabanais 

1. Nais 0. F. Miiller. Head distinct; dorsal setae begin on segment 
6 and are partly acicular and partly long and hair-like; ventral setae 
short, with cleft ends; blood yellow or red; eyes usually present: in 
standing or flowing water, in mud or on plants; reproduction by budding 
very common; 10 species, 5 American. 

N. elinguis Mull. (N. rivuloso Leidy). Two or 3 dorsal hair-like 
setae present; length 2 to 10 mm., with 15 to 37 segments; color light 
brown; eyes usually present: often abundant on algae; Europe. 

N. parvula Walton. Prostomium blunt; eyes present; dorsal bundle 
composed of 1 hair-like and 2 cleft setae; length 1.2 mm.: Cedar Point, 
Lake Erie. 

* See "Naididae of Cedar Point," by L. B. Walton, Am. Nat, Vol. 40, p. 683, 1906. 



Fig. 488 




2. Sttlabza Lamarck. Prostomium very long and tentacle-like; 
setae as in Nctis: 2 species, in Europe and America. 

8. lacuitris (L.) (Fig. 488). Length 15 mm., with 25 segments: 
common; Europe. 

8. Tamamaxb Czerniavsky. Head distinct; setae all 
forked; dorsal setae begin on segment 5; no eyes: 3 

P. litoralii (0. F. Miiller) (Enchytrceus triventrolo- 
pectinatua Minor). Length 10 nun.; segments about 20; 
blood greenish-yellow: Long Island and Vineyard Sounds, 
under stones or decaying vegetation near high-water mark 
on the seashore, also in fresh water; often very common; 

4. Dkbo Oken. Setae as in Nate; ciliated branchial 
appendages extend from the funnel-shaped rear end; 
blood reddish; no eyes: 15 species, 4 in America; often 
in tubes. 

D. limosa Leidy. Length 12 mm. or less with about 
48 segments; color reddish: in tubes at the bottom of stagnant pools 
and among algae; common; Europe. 

D. obtusa Udekem. Length 10 mm.; a long and a short seta in each 

dorsal bundle: Illinois; Europe. 

D. vaga Leidy (Fig. 489). Length 8 mm.; 
number of segments 25 to 35; body ending in 2 
long finger-like processes: often very common. 
5. Fubtxha Ehrenberg. Dorsal setae all 
hair-like and begin in second segment; ventral 
setae all forked; prostomium very long and re- 
tractile; rear end sometimes with long projec- 
tions; no eyes: 8 species, 3 American. 

P. leidyi Smith. Length 8 mm., diameter .15 
mm., with about 30 segments; 3 setae in each 
dorsal bundle, 5 to 9 in each ventral bundle; 
clitellum on segments 7 to 9 : in streams and lakes 
in the eastern and central states; common. 

P. serpentina Walton (Fig. 490). Length 2.2 
mm. with about 22 segments; dorsal bundle with 
5 to 9 setae, ventral bundle with 5 or 6: very common; Cedar Point, 
Lake Erie. 

6. Ohjbtooabteb von Baer. Very transparent worms with 2 bundles 
of hooked setae on the ventral side of each segment and no dorsal setae; 
blood colorless: 6 species, 5 American. 

Pig. 489 Fig. 490 

Fig. 489 

Dero vaga (Walton). 

Fig. 490 

PrUtina serpentina 



0. limnsi von Baer (Fig. 491). Anterior bundles of setae with 10 
to 20 each; length 5 mm.: eastern states, usually found on Lymnaa and 
Planorbis or parasitic in their liver; also free-living; common; Europe. 

0. pellucidus Walton. Setae forked, 6 to 7 
in a bundle; length 1.5 mm.: Cedar Point, Lake 
Erie; common. 


Fte.49l-Cfcartopo.t6r Family 6. TUBIPICIDAE. 

limnwi ( SQsbw. F. Deut.) 

Slender, red or brown worms living in fresh 

or brackish water in tubes from which they protrude the hinder end; 4 

bundles of setae on each segment; testes and ovaries in segments 10 or 

11; but 1 pair of sperm ducts; no reproduction by division; clitellum on 

segments 11 and 12 : about 14 genera and 50 species. 

Key to the genera of Tubificidae here described : 

<*! Dorsal setae both forked and hair-like 1. Tubifkx 

Ot Dorsal setae all forked. 

ft t Setae of segment 11 modified 3. Bothmoneubum 

6, These setae not modified. 

o 1 No blood capillaries in body wall 2. Clitellio 

c, Capillaries in body wall 4. Limnodbilus 

1. Tttbxfex Lamarck. Forked and usually hair-like setae in the 
dorsal bundles; usually forked setae alone in the ventral bundles; con- 
tractile hearts in segment 8: several species. 

T. irroratus (Verrill) (Clitellio irroratus Verr.). Pink or brown 
worms 3 cm. long; prostomium acute: near high-water mark south of 
Cape Cod on the seashore. 

T. benedeni Udekem. Gray or black worms ; cutic- 
ula studded irregularly with flattened papillae; length 
4 cm. : Long Island Sound to Maine, near high-water 
mark on the seashore. 

T. tubifex (0. F. Muller) (Fig. 492). Reddish t$/J^™ f £ 
worms about 4 cm. long with about 60 segments; the teeth (Sussw. F. 
forked setae in dorsal bundles in front of the clitellum 
have 1 to 3 middle teeth; ventral setae all forked: in mud in standing 
and running fresh water; often common, forming reddish patches on the 
mud where they are seen waving their hinder ends in the water; Europe. 

2. Clitellio Savigny. Forked setae alone present; contractile 
hearts in segments 8 and 9; no blood capillaries in body wall; prostate 
glands diffuse: 1 species. 

0. arenarius (0. F. Muller) (C. irroratus Verrill). Body very slen- 
der and reddish, up to 6 cm. long; setae sigmoid: Long Island Sound 
to Maine, often very common under rocks and stones near high-water 
mark on the seashore; Europe. 


3. BoTHBiomnum Stole. Forked setae alone present; ventral 
setae of segment 11 modified for copulatory purposes: several species. 

B. glaber Moore. Body pinkish or brown, 4 cm. long and & mm 
wide; setae short and forked at the end: Vineyard Sound, under decay- 
ing vegetation and stones near high-water mark, especially where the 
water is brackish. 

4. LnoroDBiLTTB Claparede. Forked setae alone present; contrac- 
tile hearts in segment 8 and 9; blood capillaries penetrate the body wall; 
prostate gland large and massive, in segment 11: about 10 species, in 
fresh water. 

L. claparedianus Ratzel. Length 4 to 7 cm.; segments 150: eastern 
states, in fresh water. 

L. subsalsus Moore. Body red or brown in color and 4 cm. long; 
segments 120; setae deeply bifid, 4 to 6 being in each group before and 
2 to 4 behind the clitellum : in brackish water at New Bedford, Mass. 


Small worms usually red or brown in color, living in mud in fresh 
water; 2 pairs of dorsal and 2 of ventral setae in each segment; 2 pairs 
of sperm ducts, but with 1 pair of openings: 8 genera and about 15 

1. Tbxohodxxlttb Claparede (Thinodrilus Smith). Setae simple or 
forked at the end; dorsal blood vessel with paired contractile, blind 
appendages; male pores in segment 10: 3 species. 

T. inconstans (Smith). Length 6 cm.; width 8 mm.; color reddish, 
anteriorly greenish; 5 pairs of small spermathecae : in mud or vegetation 
in fresh water. 


Usually terrestrial, sometimes aquatic oligochsts; setae curved, 8, 
12, or more on a segment; male pores on segment 18 or 17; clitellum 
beginning on or before segment 16, not appearing excepting at certain 
times and without sharp boundaries: 56 genera and about 600 species, 
principally in the southern hemisphere and the tropical portions of the 

1. Diflooabbza Oarman. Setae paired, 8 on a segment, absent on 
segment 18; clitellum on segment 13 to 18: about 10 species, all 

D. communis* Gar. Length 30 cm.; diameter 3 mm.; flesh-colored; 
dorsal vessel double; 3 pairs of spermathecae in segments 7 to 9: in the 
soil of the prairies (Illinois). 

• See "On the Anatomy and Histology of a New Earthworm (Diplocardia com* 
muni*)," by H. Oarman, Bull, of I1L St Lab. of Nat. Hiat. VoL 3, p. 47, 1892. 


D. riparia Smith. Length 25 em.; diameter 3 mm,; color brown; 
dorsal vessel single; 2 pairs of spermathecae, in segment 8 and 9: in wet 
forest soil (Illinois). 

Family 9. GE08COLECLDAE. 

Aquatic or terrestrial, usually tropical oligochots with 8 curved 
setae in a segment, paired or not; clitellum concave ventrally; male 
pores just before or in clitellum; gizzard in middle of OBSophagus: 20 
genera and about 90 species. 

Spa&ganophilto Benham. Prostomium not marked off from peri- 
stomium; clitellum in segments 15 to 25; male pores on segment 19; 4 
pairs of setae on a segment, a pair on each corner of the quadrangular 
cross section: in the mud of streams; 4 species. 

8. risen! Smith. Length 20 cm.; diameter 2.6 mm; dorsal setae 
project laterally beyond the ventral; a pair of large glands open on seg- 
ment 3; central and western states, in mud of springs. 

8. tamesis Benham. Length 10 cm. ; color red or blue; ventral setae 
project laterally beyond the dorsal: Philadelphia; England; on water 

Family 10. LTTMBRI&DAE. 

Earthworms. Terrestrial, occasionally aquatic, oligochots with 4 
pairs of setae to a segment; clitellum concave ventrally, not beginning 
before segment 18 or after segment 61; male genital pores on segment 
15 (rarely on segments 11 to 14) ; 2 pairs of testes in segments 10 and 11 
(rarely 1 pair); 1 pair of ovaries in segment 13; cocoons egg-shaped: 
5 genera and over 100 species. 

Key to the genera of Lumbricidae here described: 

Oi Peristomium completely divided doraally by prostomium (Fig. 498). 

1. LuifBBicua 
a, Peristomium incompletely divided by prostomium (Fig. 494). 
h x Gizzard occupies more than 1 segment ; clitellum reaches at least through 
segment 32. 

C| Clitellum begins mostly on segment 24 2. EissitlA 

c, Clitellum begins mostly behind segment 24 3. Helodbilus 

fr, Gizzard occupies but 1 segment; clitellum reaches at most to segment 

27 4. EisBHiDXa 

1. Luxb&xoto L. Peristomium (buccal segment) completely divided 
by prostomium (Fig. 493); setae strictly paired; 3 pair vesiculae semi- 
nales present in segments 10 and 11 which fuse together in the middle 
line; 2 pairs of spermathecae, in segments 9 and 10; tail end flattened: 
8 species, 3 American. 

0UG0CH2ETA 313 

Key to the American species of Lumbricus : 

a* Clitellum on segments 81 or 32 to 37 L. tebbestrib 

a, Clitellum on segments 26 or 27 to 32 L. bubeixus 

a, Clitellum on segments 28 to 33 L. castaneus 

L. terreetris L. (Fig. 478). Length up to 30 cm., with about 180 
segments; color purplish; clitellum on segments 31 or 32 to 37: in wet 
places; Europe and America. 

L. rubellus Hoffmeister. Length up to 15 cm. with about 150 seg- 
ments; color pink; clitellum on segments 26 or 27 to 32, usually nearly 
in center of body: in wet places; cosmopolitan. 

L. castaneus (Savigny). Length up to 5 cm. with about 90 seg- 
ments; color chestnut or violet brown, strongly iridescent; clitellum 
on segments 28 to 33: America and 
Europe. * -.^— ^ y^ 

2. BxanxA Malmgren (Allolobophora % Yl f\ /* *\ 
Eisen) (Pig. 404). Peristomium incom- i 1 f- — * 
pletely divided by prostomium; 3 or 4 Fig. 493 Fig. 494 
pairs of vesiculae seminales which do Fig. 493 — Diagram showing 
not fuse together in the middle line; 2 B^f. d KutT "^JSg 
or 3 pairs spermathecae in segments 8 to ~DS^am P showing U Tncompieteiy 
11; tail end cylindrical: 9 species, 3 g£g? P« ri8t » ml ™ < SflM "- *• 

B. fotida (Savigny). Length up to 9 cm. with about 100 segments; 
color pink with a dark ring on each segment ; clitellum on segments 24, 
25, or 26 to 32; setae strictly in pairs; 2 pairs spermathecae, in segments 
9 and 10: the worm lives often in manure and has a disagreeable odor; 

E. rosea (Sav.). Length up to 6 cm. with about 150 segments; 
color red; clitellum on segments 24, 25, or 26 to 32; 2 pairs of sper- 
mathecae in segments 10 and 11; setae strictly paired: in wet places; 

3. HSLODBILTO Hoffmeister (Allolobophora Eisen). Peristomium 
incompletely divided by prostomium (Fig. 494) ; 2 to 4 pairs vesiculae 
seminales which do not fuse together in the middle line; tail end cylin- 
drical: 54 species, 10 American. 

H. caliginosus (Savigny). Length up to 17 cm. with about 250 nar- 
row segments ; color very variable, being gray, pink, yellowish, or bluish, 
but never purple; clitellum on segments 27 or 28 to 35; setae strictly 
paired; 4 pairs vesiculae seminales; 2 pairs spermathecae: in fields and 
gardens; cosmopolitan. 

H. chloroticus (Sav.). Length up to 6 cm. with about 125 seg- 
ments; color variable, but never purple; clitellum on segments 29 to 37; 


setae in pairs, close- together; 3 pairs of spermathecae in segments 
9, 10, 11 j 4 pairs vesiculae seminales: terrestrial; cosmopolitan. 

H. palustris* (H. F. Moore). Length 7 cm.; segments 100; color 
red; clitellum on segments 23 to 28; 2 pairs vesiculae seminales; no 
spermathecae: Pennsylvania to North Carolina; in wet soil. 

4. Eibsniella Michaelsen (AUurus Eisen; Allolobophora Eisen). 
Peristomium incompletely divided by prostomium (Fig. 494), clitellum 
beginning with the segment 23 or in front of it; male pores on segment 
11 to 15; gizzard confined to segment 17; 4 pairs vesiculae seminales, 
which do not fuse in the middle line: 2 species. 

E. tetraedra (Savigny). Color yellow, brown, or blackish; hinder 
and middle portions of body rectangular; length 5 cm.; thickness 4 mm.; 
segments 90; male pores on segment 13, female pores on segment 14; 
clitellum on segments 22 or 23 to 27: cosmopolitan; in wet soil. 

Order 3. ECHlURTDA-f 

Thick-bodied, cylindrical annelids in which the segmentation is 
wanting or indistinct in the adult. The animals are, however, born as 
typical trochophore larvae and at an early period of the metamorphosis 
have fifteen rudimentary somites. Parapodia and cephalic appendages 
are wanting. A pair of large setae is present on the ventral side near 
the forward end; in Echiurus two groups of setae are also present at the 
hinder end. 

The formation of the head is peculiar. The prostomium is very 
much elongated and forms a long spatulate or trough-like structure in 
front of the mouth, which may be very elastic and forked at the end. 
The grooved ventral surface of the prostomium is ciliated and in it the 
minute animals which constitute the food of the worm are swept into 
the mouth. The prostomium is called the proboscis. 

The alimentary canal is much longer than the body and terminates 
with the anus at the hinder end; joining the rectum is a pair of long 
cylindrical anal pouches which communicate with the body cavity and 
are modified nephridia. From one to three pair of typical nephridia are 
also present in the forward part of the body. The vascular system con* 
sists of a dorsal and a ventral longitudinal blood vessel, which join each 
other anteriorly, and no lateral vessels. The nervous system includes 
a ventral chord which is segmented in the early developmental stages 
but unsegmented in the adult. A distinct brain is wanting, but an 

• See "On the Structure of Bimastus palustris, a New Ollgochete," by H. F. 
Moore, Jour. Morph., Vol. 10, p. 473, 1895. 

t See "Thallasema mellita," by H. W. Conn, Stnd. Biol. Lab., J. H. U. f Vol. 3, 
1884. "North American Bchiurlds," by C. B. Wilson, Biol. Bull., VoL 1, p. 163, 1900. 



oesophageal ring is present which is much elongated, as it extends from 
the front end of the prostomium to the ventral chord back of the month. 
Special sense organs are wanting but the prostomium acts as a feeler. 

The animals are unisexual, the gonad being unpaired but 

the ducts paired. 

The Echiurida are marine worms which live in the 

sand and mud or between stones, usually near the shore. 

The order contains about 20 species and 5 genera, 3 genera 

and 5 species being known on the Atlantic and 1 species 

on the Pacific coast. 

Key to the genera of Echiurida here described: 

Ox Preanal bristles present 1. Bobiusus 

a, No preanal bristles 2. Thalassima 

1. EoHnrKirg Cuvier. Preanal bristles and 2 ventral 
hooks present; body marked with rings bearing spines; 
2 or 3 pairs of nephridia: 3 species. 
**S setae?" E ' Pallasi Gulrin (E. chrysacanthophorus Pourtales) 

(Fig. 495). Proboscis spoon-shaped but cylindrical at 
base; about 22 body rings present; color gray, yellow, or 
orange; length 30 cm. or less; length of proboscis 6 cm.; 
width 6 cm.: North Atlantic (Casco Bay) and Alaska; 

2. Thaiassexa Gaertner. Proboscis rather pointed at 
end; no preanal bristles but 2 ventral hooks present; 1 to 
4 pairs of nephridia : 12 species. 

T. melitta Conn (Fig. 496). Color dull red with 8 Ion- _ MtyA 

Fig. 496 

•gitudinal bands; proboscis light yellow; length 25 mm., ThaloBiemo 
exclusive of proboscis, which is long and flexible: (original) 

drawing by 

Beaufort, N. C, often in sand-dollar shells. H. W. Conn). 


Fig. 495 




Class 3. HIRUDINEA.* 

Leeches (Fig. 501). Dorso-ventrally flattened, often brightly col- 
ored annelids, which are completely segmented internally and are marked 
externally with three or more rings to each somite. A large sucker is 
present at the hinder and a small one at the forward end by means of 
which the animal moves on hard surfaces. Parapodia, tentacles, and setae 

• See Leeches of the U. S. Nat. Museum," by J. P. Moore, Proc. U. 8. Nat. Mas., 
YoL 21, p. 543, 1898. "The Hirudlnea of Illinois," by J. P. Moore, Boll. I1L St Lab., 
Vol. 5, p. 470, 1901. "Notes on the Leeches of Nebraska," by H. B. Ward, Studies 
from the Zool. Lab. Neb., No. 51. "Hirudlnea and Ollgocheta Collected In the Great 
Lake Region," by J. P. Moore, Bull. U. S. Fish. Bur., Vol. 26, p. 155, 1905. "Die 
Sflsswasserfauna Deutschlands, Hirudlnea," by L. Johansson, 1909. "The Leeches of 
Minnesota," by J. P. Moore, Part III, Geog. and GeoL Sur. Minn., 1912. 


are wanting. AcanthobdeUa, a Russian fresh-water leech, is an exception 
to this rule, having setae on the first five somites. Paired gills are present 
in a few genera. The head is not distinctly marked off from the trunk 
bat the prostominm projects in front of the mouth, as in the OUgochata. 
The body cavity differs in character from that in most other annelids in 
that it is filled secondarily with a vacuolated parenchyma; several tube- 
like spaces are, however, still left in it which are connected with the 
vascular system and contain blood. 

The month is ventral or subtermihal in position and opens into a 
pharynx which is provided with salivary glands and in turn leads into 
the oBSophagos and the large crop; this organ has paired segmental 
poaches and passes back to the stomach, which may also be provided 

with paired pouches. The short intestine passes to the 
anas at the hinder end of the body above the sucker. 
The pharynx (Fig. 487) is provided with three serrated 
chitinous plates in the medicinal leech and its allies, by 
means of which the animal may draw blood from the 
body of its host The RhynchobdeUidae, on the other 
hand, have no such plates bat a proboscis which can be 
thrust oat of the mouth and be made to pierce the skin 
of another animal. The main vascular system consists 
in general of four longitudinal blood vessels, a dorsal, a 
anterior endToi ventral, and two lateral. The excretory system consists 
leech 1 ; 6 B,°ante- of paired nephridia in the middle portion of the body 
rbynchobdeiud (seventeen pairs in Hirudo), the inner ends opening into 
1, chitinous the sinuses representing the body cavity. The nervous 
{ended probo* system is like that of other annelids. The two longi- 
:&«.** ° ral tadinal nerves are close together and several of the 

anterior ganglion pairs are fused together forming an 
infra-CBSophageal ganglion. The special sense organs consist of a number 
of pairs of eyes (in Hirudo five) at the forward end of the body and sense 
buds which are most numerous at the forward end. 

The leeches are hermaphroditic. A number of pairs of testes alter- 
nate usually with the segmental lateral poaches of the digestive tract 
and communicate with a pair of vasa deferentia which proceed to the 
male genital pore in the anterior part of the body, joining to form a 
penis at their anterior end. The female pore lies just behind the male; 
two ovaries are present which are joined by the oviducts with the vagina. 
Fertilization is effected by means of a spermatophore and the eggs are 
usually laid in a cocoon formed by a clitellum on the ninth, tenth, and 
eleventh somites. The young animal is born with the form of the 


Leeches are mostly aquatic animals which live in fresh water in all 
parts of the world; a few live in the sea and a few in moist earth. They 
are predacious animals, feeding on oligochiets, snails, and other small 
animals and are also at times external parasites, sucking the blood of 
aquatic vertebrates. The class contains two orders and about 150 

Key to the orders of Hirudinea: 

0i Proboscis present and no jaws ; blood colorless ; somites rarely consisting 

of 5 rings each 1. Rhynchobdellida 

o» No proboscis but usually 3 jaws present; blood red; somites usually 

consisting of 5 rings each 2. Gnathobdellida 



Leeches with a proboscis which can be thrust out of the mouth, and 
no jaws, and with colorless blood; segments consisting of 3 or more but 
rarely of 5 rings each : 2 families. 

Key to the families of Rhynchobdellida: 

«t Both suckers distinct from body 1. Ichthtobdellidai 

o» Hinder sucker distinct, forward sucker more or less fused with body. 



Leeches parasitic on fishes, tortoises, and some other animals; both 
suckers pedunculate; body elongate, narrow anteriorly, and broad pos- 
teriorly; body segments containing more than 3 rings each: 7 genera. 

Key to the genera of Ichthyobdellidae here described : 

<h No gills present 1. Piscicola 

a. Gills present. 

6 t Paired papilliform vesicles act as gills 2. Cystobbanchus 

b» Paired arborescent gills present 3. Bbanchellion 

1. Pxboioola Blainville. Body cylindrical, distinctly 
annulated with many (usually 14) rings to a somite; eyes 
distinct: many species. 

P. rapax (Verrill) (Fig. 498). Body long and slender, 
dark olive in color with a row of rectangular white spots 
along each side; length 40 mm.; width 2 mm.: on the 
summer flounder. S£, 49 & 

P. funduli (Verr.). Body smooth, distinctly annu- (VenSS) 
lated, light green in color with fine dots of brown and 
green; length 18 mm.; 2 large and 2 small eyes: on Fundulm 

• See "Some North American Freshwater Rhynchobdellida and Their Parasites," 
by W. B. Castle, Bull. Mus. Comp. Zool., Vol. 36, p. 17, 1900. 


2. Otbtob&ahobub Diesing. Gills present in form of paired papil- 
liform vesicles along the sides of the body; body composed of 2 regions, 
a narrow anterior region of 11 somites and a broad posterior region; 
each segment contains 7 rings: 2 species. 

0. vividus Verrill. Body with 11 pairs of vesicles, brownish or 
purplish in color with 3 irregular rows of white spots on the back; 
length 25 mm.; eyes 4: on Fundulus pisculentus; Long Island Sound; 
also in fresh water. 

3. Bbahoezilzoh Savigny. Gills present in form of paired 
aborescent appendages; body with a slender anterior neck: several 

B. raveneli (Girard) (Fig. 499). Body with about 30 pain of 
gills, dark brown or purple in color; length 6 cm.: on skates and 


Fresh-water leeches in which the anterior Backer is fused with the 
body and the posterior sucker is distinct; each segment contains 3 
rings ; no cocoon is formed, the eggs and young being fixed 
to the mother's body: several genera. 

1. Glossiphohia Johnson (Clepdne Savigny). Body 

wide, attenuated forward, often brightly 
colored; animal cannot swim but rolls 
up when alarmed: numerous species; in 
fresh water. 

G. parasitica (Say) (Clepsine plana 
Whitman). Body broad and flat, with a 
smooth surface; color variegated, being 

Pig. 499 — BrancheTHon raveneli . , „ . , ... . ., ,. . 

(Verrill). pig. 500— Gio«*iphon<a greenish or yellowish, with longitudinal 

complanata — anterior end showing * . « « , .. *. 

eyes (Stissw. F. Dent). rows of spots; lower surface longitudi- 

nally striped; 2 eyes; length 6 cm.; 
width 2.6 cm.: the most abundant American species; on turtles or 
under stones. 

G. complanata (L.) (Fig. 500). Body 30 mm. long and 10 mm. 
wide, very flat; color greenish, spotted with yellow; eyes 6, in 3 pairs: 
often common under stones in running water; very active; Europe. 

G. fusca Castle (G. Uneata Verrill). Body 12 mm. long, flat and 
broad, with 12 longitudinal brown stripes; 2 large eyes: in cold 

G. elegans (Verr.) (Fig. 601). Body elliptical, 18 mm. long and 
7 mm. wide, brownish in color; head colorless; 6 eyes: abundant in 
shallow waters, often with G* stagnate; sluggish in its movements. 



G. rogosa (Verr.). Body rough and papillose; color variegated, 
Spotted irregularly with yellow and green; 2 eyes; length 5 cm,: abun- 
dant under stones in run- 
ning water. 

0. stagnalis (L.) 
(Fig. 602). Body small, 
rather elongate, grayish 
or pinkish in color, and 
25 mm. long by 2 mm. 
wide when extended; 10 
mm. long at rest; annu- 
lation distinct; 2 eyes; 
between rings 12 and 13 is a con- 
spicuous brown, cuticular plate; crop f 
with but one pair of pouches: in 
ponds and sluggish streams, where it 

feeds on small snails; very common; * 

Europe; very active in its move- 

O. hettrocUta (L.) (Fig. 603). Body 
transparent, yellowish or brownish in 
color, about 10 mm. long and 3 mm. 
wide, and with indistinct rings ; 6 eyes 
arranged in pairs at the corners of a 
triangle: in ponds and sluggish 
streams; Europe. 

2. Hmonraa Vej- 
dovsky. Anterior seeker 
pedunculate; body wide 
and flat: several species. 
B. caxinaU Verrill. 
Body 35 mm. long, rather 
slender; color greenish 
with longitudinal stripes ; 
eyes 2, conspicuous : com- 
mon in streams, some- 
times attached to frogs 
or toads. 

Jig. fiOl— aiostivlivtHa * 

diagram allowing the digestive and 
genital tract!, seen from the dorsal 
surface, the somites being numbered 
on tbe left and the rings on the 
right aide (Castle), an., anus; br„ 
brain; cr., crop; In., Intestine ; ov., 
OTary; pr., proboscis ; p.s., poste- 
rior socket ; a]., salivary glands ; 
st.. atoms cb ; t, test Is ; d, male 
' genital pore ; V, female genial pore. 

Freeh-water and terrestrial leeches without a proboscis and usually 
with 3 jaws (Fig. 497, A); blood red: 2 families. 


Key to the families of Gnathobdellida : 

«, Three toothed jaws present 1- Hibudinidab 

a, Three unarmed muscular ridgee present in place of the jaws. 


Family 1. HIRUDIN IDAE. 
Leeches with 3 toothed jaws; segment contains 5 rings; 5 pairs of 
eyes: several genera, 

1. Hi&udo L. Elongate, flattened leeches with about 95 annota- 
tions; margin of body serrate; crop with about 10 pairs of lateral 
pockets; teeth very numerous, over 100 in 
number; body contracts and does not roll 
£ up: numerous species. 

ft H. medidnalia L. The medicinal leech. 

» Body yellowish-brown, 10 to 20 cm. long: 

H an European animal which has been intro- 

H duced into some ponds and streams in the 

flg eastern United States; used for blood- 

Bm letting. 

Jg 2, Ejekdpii Bavigny. Body rather thick, 

j^H with smooth margins; crop with 1 pair of 

IfS croea but without lateral pockets; teeth few, 

Kjl about 20 ; 5 pairs of eyes. 

BBl h - maxmoratis (Say). The horseleech. 

WHk Body 10 cm. long or more, 15 mm. wide, 

^VBBr smooth, and very soft; color variegated, 

being blackish or brownish, blotched with 
irregular spots: in the mud at the aide of 
pools and streams and also occasionally 
on the land; will occasionally suck blood but usually eats worms, 
snails, etc. 

H. grandls (Verrill). Body 20 cm. long or more, specimens 45 em. 
having been found; color yellow, mottled with black; the largest 
American leech: New England, the Great Lakes, and westward. 

S. Magrobdelu, Verrill. Body strongly annulated, broad and flat- 
tened, and tapering but little; about 05 teeth on eaeh jaw; male orifice 
between segments 26 and 27 and the female orifice between segments 
31 and 32: 3 species. 

M. decora (Say). Body up to 30 cm. long and 25 mm. wide, brown 
or olive green in color, with a median row of about 20 red spots and a 
row of black spots near each margin; lower surface reddish: very com- 
mon in fresh water, a fierce blood sucker, attacking men, cattle, fish, 
frogs, etc., but also eating other animals. 



Body subcylindrical, elongate with 3 unarmed muscular ridges in 
place of jaws; crop without lateral pockets: several genera. 

1. Hkbfobdella Blainville (Nephelia Savigny). Body long and 
narrow and with smooth margin; segments contain 5 rings each; genital 
orifices separated by 2 or 3 rings; many species; on plants and on the 
under side of stones in streams. 

H. punctata (Leidy) (Pig. 504). Body up to 10 em. long and 1 cm. 
wide; color brownish-black with 4 longitudinal rows of irregular black 
spots; 3 pairs of eyes: common in streams and pools. 

H. (Dina Blanchard) fervid* (Verrill) (Pig. 505). Body up to 5 
em. long, variegated pale red in color; 3 or 4 pairs of eyes: abundant 
in the Great Lakes region. 

Class 4. M7Z0ST0MIDA.* 

These animals are small disc-shaped parasites of crinoids, ophiurans, 
and starfishes, on the bodies of which they live either in cysts or free. 
The body is oval in outline, much flat- 
tened, and externally unsegmented. 
possesses, however, five pairs of pai 
podia, each of which is stiffened 
two setae, and four pairs of latei 
ventral sucker-like organs which 8 
probably sense organs. The edge 
the body is serrate in some species ; 
others ten pairs of short cirri exte 
from it. A distinct head is not pn 
ant (Fig. 506). 

The body cavity is obliterated by ^ ooe-Megram of « m,«>.tomiJ 
the growth of a vascular parenchyma i'jSSa^Ui^^SaSI 
throughout it. The month is ventral «gjga l W>ffi: Vffiiakj 
in position and near the anterior end J**™"* ; "■ """ ; "' m " le t^Ul 
of the body; it opens into the pharynx, 

which forms a proboscis. The intestine is straight and sends out a num- 
ber of long branches on each side. The anus is near the hinder end of the 
body. Special vascular and respiratory organs are wanting; nephridia are 
present. The nervous system is highly specialized. It consists of two 

* Bee "Venelebnl» der tod den 17. 8. Cout Survey Steamer* Hauler nnd Blake, 
Ton 1887-1879, geaammelten Myioatomldeen," by L. von Graff, Bull. Hoa. Comp. 
ZooL, Vol. 11, p. 125. 1888. 'The Seiua! Phages of Myioatoma," br W. M. Wheeler, 
Mitt ana d. ZooL St to Neap., Vol. 12, p. 22T. 1896. "New Marine Worms of the 
Henna Mywmtoina," br 3. F. HcClendon, Proc. U. 8. Nat Mna., Vol. 82, p. 63, 1907. 


oesophageal nerve rings and a large ventral nerve mass which is composed 
of about six fused pairs of ganglia and sends off numerous nerves. No 
special sense organs are present. The animals are hermaphrodite. The 
testes are paired, branched organs which are joined on each side by two 
vasa deferentia with a lateral sperm sac; this opens to the outside by a 
marginal pore near the middle of the body. Two ovaries are present; the 
ova are collected in a median uterus which communicates with the rectum. 

The class includes over 70 species and 2 genera. 

Mtzostoxa F. S. Leuckart. With the characters of the class: 
numerous species. 

M. glabrnm F. S. Leuck. Body nearly circular, 4 mm. long, with 10 
pairs minute protuberances; parapodia short; cloaca dorsal: Europe, on 
Antedon rosacea, attached to the oral plates. 

M. cnbannm McClendon. Diameter 1.7 mm.; thickness .08 mm.; 
dorsal surface flat, with 10 pairs of short conical cirri; ventral surface 
convex; parapodia prominent; suckers absent: West Indies, from 
crinoids off Havana. 


ARTHROPOD A. (Crustaceans, Arachnids, Myriapods, 

and Insects.) 

Animals which are externally segmented and have segmented ex- 
tremities (Fig. 542, A). 

External Structure.— The segmentation of arthropods is heterono- 
mous, the somites or body segments being unequal in size, and in most 
cases the body is made up of three divisions, the head, the thorax, and 
the abdomen. Fusion occurs very frequently between contiguous somites 
so that their boundaries are obliterated: the somites of the head are 
always thus fused. The appendages or extremities are elongated, seg- 
mented projections of the ventral body wall, there being typically a 
single pair on each somite except on the terminal one. In many 
cases where the segmentation has disappeared secondarily the number 
of pairs of appendages gives a clue to the number of somites originally 

The appendages are primarily locomotory and sensory organs, but 
we find them performing many other functions. The first pair forms 
the antennae or feelers, where these are present, and their function is 
usually purely sensory. One or more pairs form the jaws, which have 
thus a right and left position. The appendages of the middle and hinder 
part of the body usually preserve their locomotory function and form 
the walking or swimming legs. These, however, often serve also other 
purposes, as for respiration and the transportation of eggs or young, or 
as spinnerets in spiders, and as stings, anal feelers, and ovipositors 
among the insects. 

The following scheme taken from Korschelt & Heider's Textbook of 
Embryology illustrates the homologies of the anterior pairs of appendages 
in the principal groups of Arthropoda: 




Antennae 1. 


Antennae 2. 





Maxillae 1. 

Legs 1. 


Maxillae 2. 

Legs 2. 


Thoracic appendages 


Legs 3. 

Legs 1. 

Thoracic appendages 


Legs 4. 

Legs 2. 

Thoracic appendages 


Legs 3. 



The largest group of arthropods, the insects, is distinguished by the 
possession of wings, two pairs of which are typically present, arising as 
projections from the dorsal wall of the thorax. 

The principal organs of special sense are the eyes, the tactile hairs, 
and the auditory or balancing organs. The tactile hairs are usually dis- 
tributed over the body, but are probably most sensitive on the antennae 
and the palps, where they are organs of touch, hearing, taste, or smell. 
The eyes are of two kinds, simple and compound. A simple eye or 
ocellus is a minute structure formed by a modification of the integu- 
ment and consisting of a convex retina and a lens. A compound eye is 
a much larger and more complex structure and consists of a large number 
of distinct elements called ommatidia. Each of these is a separate light- 
perceiving body, and the sum of the images of all the ommatidia of a 
compound eye forms the picture the animal sees. This is called mosaic 
vision and characterizes crustaceans and insects alone among animals. 
A pair of lithocysts, or so-called auditory organs, are present in certain 
crustaceans; they are organs of equilibration. A few species of insects 
have genuine auditory organs. 

The integument of arthropods is composed of a shell-like cuticula 
which forms the entire outer surface, and a layer of glandular cells called 
the hypodermis which lies beneath the cuticula and secretes it. The 
cuticula is rendered tough and thick by the presence of chitin and 
sometimes of calcium carbonate and forms a very efficient outer cov- 
ering. During the period of growth an arthropod sheds its cuticula 

Arthropods are often highly colored, some of them being among the 
brightest of animals: many are protectively colored and many crustaceans 
are transparent, being almost invisible in the water in which they live. 
Sexual dimorphism is very common, the males being distinguished from 
the females by size, color, or other external markings. 

Interned Structure.— The digestive tract extends from the mouth to 
the anus and is made up of f oregut, midgut, and hindgut, which, however, 
in all arthropods have undergone a large degree of specialization. Sali- 
vary glands are generally present in the terrestrial arthropods but are 
absent in the aquatic ones. Other digestive glands are wanting in insects, 
but in crustaceans and arachnids a voluminous liver is often present. 
The excretory organs or kidneys are present in the form of one or more 
pairs of tubular glands. 

The circulatory system is not highly specialized. A blood fluid is 
always present which circulates among the organs in the extensive body 
cavity. In many small crustaceans no heart or other vessels are present, 
but the circulation is maintained by the movements of the intestine or of 


the whole body. In most arthropods, however, a heart, usually tubular 
in shape, is present in the dorsal part of the body cavity, the beating of 
which keeps the blood in circulation. In no arthropods, however, is there 
a closed vascular system, as the blood, even in the highest, passes from the 
tissues to the respiratory organs through open spaces of the body cavity. In 
most arthropods respiratory organs in the form of projections from the 
legs or the sides of the body are present. In the crustaceans these pro- 
jections extend into the water and form the gills, while in the air-breathing 
forms the projections extend into the body cavity and become the so-called 
lungs of the arachnids or the tubular tracheae which carry respiratory 
air directly to the blood. The muscular and nervous systems of arthro- 
pods are highly developed. The muscles are all striated and are probably 
the most energetic among animals. 

The main nervous system, like that, of annelids, consists of a number 
of pairs of segmentally arranged ganglia and nerves connecting them. 
The anterior pair constitutes the brain and is situated in the' dorsal 
portion of the head; from it nerves go to the eyes and the antennae. 
The remaining parts are ventrally situated, one pair being typically 
in each somite. In most arthropods, however, fusion has occurred among 
the ganglia so there are fewer pairs of them than of somites. This fusion 
has gone so far in some of the highest arthropods that all the ventral 
ganglia have come to form a single mass. In all arthropods the brain 
is distinct and is joined with the ventral ganglia by a pair of connecting 
nerves, one of which passes on each side of the OBSophagus. 

With a few exceptions arthropods are unisexual, the hermaphroditic 
forms being a few parasitic or sessile crustaceans and a few arachnids. 
The gonads are usually paired, tubular glands which open to the outside 
by a pair of openings in crustaceans and by a single median abdominal 
opening in most other arthropods. Parthenogenesis occurs among certain 
crustaceans and insects, and pedogenesis occurs as a rare phenomenon 
among the latter. 

Arthropods are generally characterized by the care they take of their 
eggs and young. Many of them carry their eggs until they hatch, and 
often the young animals are also carried. Among insects a family life 
of remarkable complexity characterizes many species, which often leads 
to the formation of colonies characterized by a division of labor among 
their individual members, as in the case of the bees, termites, and many 

Distribution.— Arthropods constitute the largest phylum of animals, 
numbering about 400,000 known species, or four-fifths of all known spe- 
cies of animals. They form also one of the most widely distributed 
groups, being found in all parts of the sea and land. The crustaceans 


are almost exclusively aquatic and the arachnids and tracheates almost 
exclusively terrestrial and aerial animals. 

History.— Linnaeus gave the name Insecta to all the animals which 
are now included under the Arthropoda, the crustaceans, spiders, and 
myriapods being Insecta aptera. Cuvier in 1800 created the Crustacea 
as an independent class, and Lamarck in 1801 performed the same service 
for the Arachnida, restricting the term Insecta to the Hexapoda and the 
Myriapoda. The last-named group was created in 1796 by Latreille. All 
these animals were joined by Cuvier with the Annelida to form the Ar- 
ticulata, but in 1845 von Siebold separated the Annelida from the others, 
making a class of them under the Vermes, and formed an independent 
group of the Crustacea, Arachnida, and Insecta to which he gave the name 

The phylum contains 3 classes. 

Key to the classes of Arthropoda: 

Ox Aquatic arthropods (with a few exceptions) having gills and 2 pairs of 

antennae 1. Crustacea 

o, Air-breathing arthropods (with a few exceptions). 

&! Antennae absent 2. Abachnoidea 

b t One pair of antennae present 3. Tbacheata 

Class 1. CRUSTACEA.* 

Aquatic arthropods which breathe by means of gills and have 2 pairs 
of antennae and biramose appendages (Fig. 542). 

External Structure.— An elongated body with distinct segmentation, 
in which the primary division into head, thorax, and abdomen is evident, 
characterizes most crustaceans. A tendency is however present in all the 
groups towards a fusion of the somites and a shortening of the body. 
Those forming the head are always thus fused and are besides often 
joined with some or all of the thoracic somites, forming thus a body 
division called the cephalothorax, which in many crustaceans is wholly or 
partly covered by a bivalve shield called the carapace. 

The appendages are fitted primarily for locomotion and respiration in 
the water and are typically biramose, each consisting of a basal piece, the 
protopodite, and two segmented, terminal pieces, an outer one, the exopo- 
dite (Fig. 516, 16) , and an inner one, the endopodite (Fig. 516,17) . Although 
this is the primitive condition of the appendage, the performance of special 
functions has in many cases brought about a modification of it and often a 
loss of some of its parts. 

* See "Crustacea/' by A. Gerstaecker and A. E. Ortmann. Bronn's "Klass. xu 
Ord. d. Thierreichs," Bd. 5, Abt. 1 and 11, 1866-1901. "Crustacea/' by J. S. Klngsley, 
Standard Natural Hist., Vol. 2, 1888. "List of the Crustacea/' by Mary J. Rathbnn, 
Fauna of New England in Occasional Papers of the Boston Soc. of Nat Hist., VII, 


Five pairs of Appendages are present in the head, the first antennae, 
second antennae, mandibles, first maxillae, and second maxillae. Of these, 
the first pair of antennae (antennnles) differs from all the other append- 
ages of the body in not being typically biramose; they are not, however, 
necessarily simple, but the distal portion of the appendage is frequently 
split into two, three, or more branches, called flagella (Fig. 614,1). The 
mandibles are short, stout appendages, fitted for biting, and may bear a 
sensory palp which is the modified endopodite, the exopodite being want- 
ing. The two pairs of maxillae are usually delicate structures whose 
function is probably chiefly sensory. 

The number of thoracic appendages varies greatly among crustaceans. 
The smallest number of pairs (2) is found among ostracods and the 
largest number (60) among the Apodidae. The abdominal appendages 
are wanting in the Entomostraca and in the youngest larval forms of 
most Malaco8traca. In adults of the latter group, however, these are 
present on ail the abdominal segments except the last one (telson). 

The cuticula of crustaceans is shed periodically. In the smaller 
species it is very delicate and the animal is often quite transparent. In 
the large Malacostraca it contains calcium carbonate as well as chitin and 
is very hard and thick : it is such animals which have given the group the 
name Crustacea. 

Internal Structure (Fig. 623).— The digestive tract is in most crus- 
taceans a straight tube going from the ventrally located mouth to the 
anus at the hinder end of the body. Tubular livers, often very volumi- 
nous, are present in most forms; salivary glands are absent. The ex- 
cretory organs consist of a pair of tubular glands, the kidneys, which 
open to the outside in the neighborhood of the mouth. The respiratory 
organs are lacking in some of the small crustaceans, the outer surface of 
the body performing this function. In most of them, however, gills are 
present, fes projections of the thoracic or abdominal appendages or of 
the sides of the body. 

With the exception of most of the Cirripedia, which are all either 
sessile or parasitic, all crustaceans are unisexual. Among the Phyllopoda 
and Ostracoda parthenogenesis is common. In the lower crustaceans the 
animal usually leaves the egg as a nauplius larva, a minute animal with 
three pairs of appendages, of which the first pair is uniramose and the sec- 
ond and third pairs are biramose. With a few exceptions (Peneus, Lucifer) 
all the higher crustaceans pass through the nauplius stage while still in 
the egg and are born in some later stage of development. Many of them, 
as the crayfish, have the form of the adult when born, the entire meta- 
morphosis having been completed in the egg. 

Habits and Distribution.-- The sowbugs, land crabs, and a few other 


forms live on the land, but all others are aquatic animals. The majority 
of these live in the sea, the PhyUopoda being the only order which is 
better represented in fresh than in salt water. Crustaceans feed largely 
on decaying animal and plant substances. Many are parasitic, especially 
among the Copepoda, Cirripedia, and Isopoda, The barnacles are the 
only sessile crustaceans. 

History.— Crabs and other decapods have been known and used for 
food from time immemorial. They were first described by Aristotle who 
calls them Malacostraca or soft-shelled animals in contradistinction to the 
hard-shelled mollusks. Linnaeus placed them among the Insecia aptera. 
The lower crustaceans were seen by the earlier microscopists, but very 
little studied or understood until the time of 0. F. Miiller, who in 1785 
brought together a large number and called them Entomostraca, or insect- 
like crustaceans. Cuvier, Latreille, and Lamarck in the first years of the 
new century introduced the term Crustacea to include all crustaceans, 
although the term had already been used as a synonym of Malacostraca, 
The creation of the various orders of crustaceans is largely due to La- 
treille, who introduced the names Branchiopoda, Isopoda, Amphipoda, 
Decopoda, and PhyUopoda. Milne-Edwards formed the order Copepoda, 
and Burmeister introduced the terms Arthrostraca and Thoracostraca. 

American crustaceans have attracted many able investigations from 
the time of Thomas Say in the first quarter of the last century to the pres- 
ent time. In 1852 appeared the Crustacea of the Wilkes Expedition, by 
James Dwight Dana, which was one of the most important zoological 
works of the day. This and the works of Say, Stimpson, S. I. Smith, 
and others form the groundwork of our present knowledge of American 

The class contains about 16,000 species, grouped in 2 subclasses. 

Key to the subclasses of Crustacea: 

Ox Small, often minute crustaceans without abdominal appendages. 

1. Entomostraca 
a, Larger crustaceans usually with abdominal appendages. . .2. Malacostbaoa 

Subclass 1. ENTOMOSTRACA. 

Small crustaceans, the majority of which are under a centimeter in 
length; somites variable in number; head, thorax, and abdomen usually 
distinctly marked, but in many the head and one or more thoracic somites 
are fused together, forming a cephaJothorax ; body either elongate with 
distinct segmentation or much shortened and enclosed in a chitinous shell 
called the carapace; parasitism has produced great changes in the form 
of many entomostraceans so that all semblance of the crustacean form is 
often lost; appendages confined to the head and the thorax, 5 pairs being 


cephalic and the thoracic appendages varying in number from 2 pairs 

to 60 : 4 orders with about 4,800 species. 

Key to the orders of Entomostraca: 

Qg Free swimming or parasitic on fish (rarely on other animals). 
Ot Thoracic appendages flattened and leaf -like; body either elongate and 
segmented or short and more or less covered with a carapace. 

1. Phyllopoda 
&j Body either elongate and segmented with cylindrical thoracic appendages, 

or greatly modified when the animals are parasites 2. Copepoda 

6, Body short and unsegmented and entirely enclosed in a bivalve cara- 
pace 3. Ostbaooda 

•t Body sessile and enclosed in a calcareous shell (barnacles) or parasitic 

on decapods or mollusks 4. Cibmpedia 


Thoracic appendages fiat and leaf -like, as the name indicates, being 
organs of respiration; body either long and vermiform and composed 
of numerous segments or short and compact and unsegmented; carapace 
usually present; parthenogenesis common, the usual eggs being relatively 
small and thin-shelled and called summer eggs; at the approach of 8 
period of drought or cold males are born from the parthenogenetic eggs 
which fertilize the females, and the eggs which these then lay are large 
and thick-shelled and called resting or winter eggs, and are capable of 
enduring the winter's cold or the summer's drought, if need be: 2 sub- 
orders and more than 600 species, most of them being fresh-water animals, 
living in pools, lakes, and streams containing the minute algae which form 
their principal food. 

Key to the suborders of Phyllopoda: 

o, Body elongated and distinctly segmented 1. Bbanchiopoda 

Ob Body short with indistinct segmentation or without any, and usually with 

a bivalved carapace 2. Claoooeba 

Suborder 1. BRANCHIOPODA.f 

Elongated phyllopods with numerous distinctly marked segments, and 
either with or without a carapace; the young born as nauplii: several 
families and over 100 species, which, with a few exceptions, live in fresh 

Key to the families of Branchiopoda here described: 

Ox Carapace absent 1. Branchipodidae 

Ot Carapace present. 

At Carapace flattened dorsoventrally and arched 2. Apodidab 

o, Carapace compressed laterally 3. Limnadhdae 

• See "Die Sflsswasserfauna Dentschlands," Heft 10, 1909. 

f See "Phyllopod Crustacea of North America/' by A. 8. Packard, 12th Ann. Rep. 
U. S. Geol. Sur. of the Ter., 1878 (1883), pt. 11, p. 294. 



Body elongate, being composed of many segments and without cara- 
pace; head distinctly set off; first antennae filiform; second antennae of 


male used for clasping the female, being very large and composed of 2 elon- 
gated segments and with or without extra frontal appendages between 
them; thoracic segments and appendages mostly 11; abdominal segments 
8 or 9 in number; 2 stalked eyes present; a pair of egg sacs extend from 
the last thoracic segment of female: 8 genera; the animals live in fresh 
and salt pools and swim on their backs. 

Key to the genera of Branchipodidae here described: 

Oi Frontal appendages present. 

&! Frontal appendages simple in form 1. Branchipus 

6, Frontal appendages branched 2. Chibocephalus 

o, Frontal appendages absent. 

6 t Abdomen with 8 segments 3. Abteioa 

6, Abdomen with 9 segments 4. Branchinbcta 

1. B&avohipto Schaeffer. Beween the second antennae of male 
are 2 unbranched frontal appendages; abdomen consisting of 9 segments 



Fig. 507 Fig. 508 

Fig. 507 — Branchipus vernaUs — male (Packard). 1, first antenna; 2, second 
antenna; 3, frontal appendage. Fig. 508 — Chirocephalus holmoni — front view of 
bead of male (Packard). 1, eye; 2, first antenna; 3, second antenna; 4, frontal 

and 2 long caudal projections which have setose margins: 2 American 

B. vernalifl Verrill. The fairy shrimp (Fig. 507). Body semi- 
transparent and pinkish in color; length 23 mm.; frontal appendages 
broad and flat: eastern North America, in fresh-water pools during the 
spring, autumn, and winter, passing the summer as resting eggs; often 
common, but sporadic. 

2. Chibooephaxto Prevost. Between the second antennae of male 
2 very long, branched, and coiled frontal appendages; abdomen con- 
sisting of 9 segments and with 2 long, broad caudal projections with setose 
edges: 1 American species. 

C. holmani Ryder (Fig. 508). Body slender, 15 mm. long: eastern 
North America (Philadelphia, Long Island). 





3. Ahtemia Leach. No frontal appendages present; second joint of 
second antennae flat and triangular; abdomen of 8 segments and with 2 
very short caudal projections; egg sac short: several 

species, all in salt pools and lakes ; 2 American species. 

A. gracilis Verrill (Fig. 509). Body aemitranspar- 
ent, pink or green in color, 10 mm. long: eastern and 
central North America, as far west as Great Salt Lake. 

A. franriacana Kellogg. Body translucent whitish 
or dull brick red in color and slender; length 13 mm.; 
caudal appendages with setose edges: California. 

4. Bbanchthecta* Verrill. No frontal append- 
ages between second antennae, the second joint of 

, which is simple and slender; ab- ArtJai&nrocUH 

domen of 9 segments; egg sac , (HSttSSi" 

° * DO I, nret antenna 

long and slender : 3 species, in the 2 < secona antenni, 

western states. 

B. coloradensis Packard (Fig. 510). Length 18 
mm.; second antennae large, and broad and bent in, 
and not serrate: very common in Colorado. 

Family 2. APODIDAE. 
Body elongate and composed of many segments, 
and with an oval, low-arched carapace covering the 
head and thorax; eyes sessile; first antennae short and 
filiform with 2 or 3 flagella; second 
antennae minute or wanting in the 
adult; 40 to 60 pairs of broad feet, the first pair end- 
ing with 3 long, slender branches, the eleventh pair 
forming egg capsules in the female; 2 long caudal 
bristles; larva a nauplius: 2 genera; in fresh water. 
Apub Schaeffer (Triops Schrank). With the 
characters of the family: about 4 American species, 
all in the western states. 

A. lucasanus Packard (Fig. 511). Telson with 
3 central spines ; length, with caudal bristles, 41 mm. : 
western America, abundant in Kansas. 

Body elongate and entirely enclosed in an oval laterally compressed 
carapace, which gives the animal the appearance of a bivalve mollusk; 

Fig. BIO 


coloradentii — 

front view of bead 

or male <9n«nti). 


eyes sessile and close together; first antennae minute, second large, with 
2 terminal branches; 18 to 28 pairs of broad feet, the first or the first 
and second pairs being prehensile in the male: in fresh water, differing 
from the Cladocera and Ostracoda in being much larger and in having 
distinct segmentation and more appendages and an abdomen which is not 
bent under the thorax; about 5 genera. 

Key to the genera of Limnadiidae here described : 

a. Lines of growth on shell ; 24 pairs of feet 1. Cyzicub 

a. No lines of growth ; 10 to 12 pairs of feet 2. LiMNETO 

1. Otziodb Audouin {Esthe- 
ria R up pell). Shell oval and 
opaque, amber-colored ; body 
rather thick; head with a long 
narrow rostrum; about 24 pairs 
of flat feet, the first two pairs 
being prehensile in the male: 
numerous species, about 8 in 
America, all in the West. 
Fig. Slit-Ovi*™.™^ (Packard). °- morMi (Packard) (Fig. 

512). Shell 12 mm. long, 8 mm. 

high, and 6 mm. across; the two branches of second antennae with 17 

and 16 joints each: widely distributed throughout 

the central and western parts of the country. 

2. LnnrETiB Loven. Shell oval or spherical, with 

no lines of growth; head with a large rostrum; 11 or 

12 pairs of feet, the first pair being prehensile in the 

male; eggs carried in a dorsal brood chamber: 4 

species in America. 

L. gouldi Baird (Fig. 513). Body rather thick; Fig. Bi3— Umnetu 

second antennae with 16 segments in each branch; oovin (Packard). 

length of shell 3 mm.; breadth 2.5 mm.; color pink; eyes black: eastern 

and central America, westward to the Mississippi. 

Suborder 2. CLADOCERA,* 

Water fleas. Body usually short and compact, without segmenta- 
tion, and enclosed in a bivalve carapace; 4 to 6 pairs of thoracic ap- 
pendages; first pair of antennae often minute, second pair very large, 

•Sea "Notes on Clsdocera," by B. A. Blrge, Trana. Wis. Acad., Vol. 4, 1878. 
"Uit or Crnatacea Cladocera from Madison, Wis.," by name, ditto. Vol. 8, 1891. 
"Notes on Cladocera." by same, ditto, Vol. 9, 1892. "Synopala of the Ento- 
mostraca of Minnesota," etc., by C. L. Herrlck and C. II. Turner, Second Rep. of 
BWte ZooL, 188B. "The Cladocera of Nebraska," by Cbarles Fordyce, Stod. from the 
Zoo). Lab. of tne Univ. of Neb., No. 42, 1801. 


with the two branches (exopodite and endopodite) prominent, and used 

for swimming; abdomen small and usually bent under the thorax; 2 

large compound eyes which in many species unite to form a single 

median eye; a large dorsal brood sac in the female in which the eggs 

develop, the young animals being born with the form of the parent; 

the winter eggs are often provided with an extra shell ealled the ephip- 

pium, consisting of 2 chitinous plates, like watch crystals, whose edges 

fit together, one, two, or more eggs being in a single ephippium: about 

8 families and several hundred species, most of which live in fresh water. 

Key to the families of Cladocera here described : 

Ox Carapace enclosing the entire body. 
6j One branch of second antennae with 2 segments, the other with 3.1. Sididae 
6, One branch of second antennae with 3 segments, the other with 4. 

Ox First antennae minute 2. Daphnidae 

Oa First antennae long and beak-like 3. Bosminidae 

6g Both branches of second antenna with 3 segments 4. Lynceidae 

Us Carapace not enclosing the legs and the abdomen. 
&! Abdomen curved and rudimentary ; 4 pairs of legs ; fresh and salt 

water 5. Polyphemidae 

&, Abdomen straight and very large ; 6 pairs of legs 6. Leptodoridae 

Family 1. SIDIDAE. 

Head large and separated from the body by a depression and usually 
with a beak; first antennae one-jointed, but long in the male, with a 
long terminal flagellum; second antennae very long, the two branches 
having 2 and 3 segments respectively; 6 pairs of legs; heart elongate 
and intestine straight, without liver sacs: several genera. 

Key to the genera of Sididae here described : 

a\ Dorsal branch of second antennae three- jointed 1. Sida 

a, Dorsal branch of second antennae two- jointed. 

b t First joint of second antennae with a long side branch 2. Latona 

&, No such side branch 3. Dafhnella 

1. Sida Straus-Durkheim. Ventral branch of v # t 

second antennae with 2 segments; dorsal branch 

with 3 segments; beak distinct: several species. 
8. crystallina (0. F. Miiller) (Fig. 514). Shell 

elongate with rounded ends; first antennae in male 1 f J 

long, short in females ; body colorless, sometimes Big. 514 — Sida cry* 

with brown, red, and blue spots; length 2 mm.: in Deut.*° l, second" an- 

clear lakes; often widely distributed; often com- naT a £ abdomen"**? * 

mon; Europe. brood sac 

2. Latona Straus-Diirkheim. Ventral branch of second antennae 

with 3 segments, dorsal branch with 2 segments, the first segment having 
a long side branch: 1 species. 


L. sotifera (0. F. M tiller). Body and appendages very setose; color 
yellowish, often with spots; length 3 mm.: among weeds in clear lakes; 
widely distributed; Europe. 

S. Dapkhell*. Baird. Ventral branch of second 
antennae with 3 segments; dorsal branch 2 segments; 
beak absent; no teeth on the abdomen; first antennae 
iihort in female: several species. 

D. ra-achynra (Lievin) (Fig. 515). Length .7 mm.: 

in clear water; widely distributed: Europe. 

2, Brut antenna ' J t t~ 

Family 2. DAPHNIDAE. 
Body oval; head rounded, usually with a short beak; first antennae 
usually minute, consisting of a single segment; the 2 branches of the 
second antennae consisting of 3 and 4 segments respectively; 5 pairs of 
legs, the last pair separated from that nest to it; intestine not coiled 
and with a pair of liver sacs : about 12 genera. 

Fig. 618 — Paphnia pvltx (Klngsley). 1, flrat antenna ; 2, second antenna ; 3, eye; 
4. optk ganglion; 6, brain; 8. liver sac; 7, Intestine; 8, kidney; 9, heart; 10. brood 
aac with two egga ; 11, abdomen ; 12, anua ; 13, ovary ; 14, legs ; 16, month ; 16, 
exopodlte ; IT, endonodlte. 

Key to the genera of Daphnidae here described : 
a, Head terminating ventrally in a beak. 
6, Head not separated from bod; by a dorsal notch; shell with a caudal 

spine at the tipper posterior angle 1- Daphnia 

b, Such a notch present, 
c, Shell abruptly truncated behind, with a short spine at the lower 

posterior angle 2. Scapholkoebib 

c, Shell rounded below, with a blunt spine above S. SlUOCEPHAXUS 

a, No beak, or a rudimentary one. present. 

b, Abdomen not enclosed by shell 4. Moina 

6, Shell enclosing, the whole abdomen 5. Cebiodafhru 

1. Daphnia 0. F. Muller. A sharp caudal spine, extending from 
the upper posterior angle of shell; head not separated from the body by 
a dorsal notch: about 50 species. 

D. m<""*h»*'^ Herrick. Caudal spine lees than half the length of 
the shell; general form oval, tapering behind; length 1.8 nun.; a project- 



ing spur present on the dorsal margin of the head, which in males and 
young females has from 1 to 4 sharp teeth: Wisconsin and Minnesota. 

D. pnlex DeGeer. The common daphnia (Fig. 516). Body oval, 
often reddish ; a prominent beak on the nnder side of the head ; length 2 
mm. or more : very common and widely distributed in America and Europe. 

D. hyalina Ley dig (Fig. 517). Body oval; caudal spine almost 
as long as body; head extended forward in a helmet-like crest but very 
variable in shape and size; length 1.8 mm.: widely distributed in this 
country and Europe. 

2. Scapholeberis Schodler. Body short with a truncated hinder 
end from the lower margin of which a pair of caudal spines, which are 
sometimes very short, extend backwards: 6 species. 

Pig. 517 " "* Fig. 518 Fig. 510 

Fig. 517 — Daphnia hyalina (Herrlck). Fig. 518 — Scapholeberis muoronata (Herrick). 

Fig. 519 — Sitnocephalus vetulua (Sttssw. F. Deut.). 

8. mucronata (0. F. Miiller) (Fig. 518). Spines short; color dark; 
length .8 mm.: common in eastern America and in Europe. 

3. SrJCOOEFHALTO Schodler. Body obliquely truncate behind, with- 
out a caudal spine; abdomen with 2 dorsal processes: 8 species. 

8. vetnlus (0. F. Miiller) (Fig. 519). Body large, short, and high ; head 
rounded in front, 2.5 mm. long: common in eastern America; Europe. 

8. sernilatus (Koch). Head narrow, extending forwards sharply; 
length 2 mm.: central United 
States; Europe. 

4. MonrA Baird. Head with- 
out beak; first antennae long; the 
end of the abdomen not covered 
by the shell; pigment spot (acces- 
sory eye) absent: about 10 spe- 
cies; in muddy swamps, often in 
impure water. 

M. brachiata (Jurine) (Fig. 520). Body almost as high as long, 
greenish in color; 1.3 mm. long: eastern America; Europe. 

5. Ceriodaphhia Dana. No beak present; first antennae short; 
head rounded; shell oval or circular, and reticulate: about 20 species; 
often in foul water. 

0. reticulata (Jurine). Claws of abdomen dentate; length .8 mm.: 
eastern and central America; Europe. 

Fig. 520 — Moina brachiata (Herrlck). 


Family 3. BOSMINIDAE. 
First antennae greatly elongated and extending from the beak forma 
a long curved proboscis; 5 pairs of feet and rudiments of the sixth; 
second antennae small; pigment spot (accessory eye) wanting; intestine 
straight and without liver sacs : 1 genua. 

Bosktjia Baird. With the characters mentioned above: about 20 
, species; mostly bottom forms. 

B. longirortris (0. F. Miiller) (Fig. 521). 
Shell oval with hexagonal markings and with 
1 a caudal Bpine projecting from the ventral 
margin; length .35 nun.: very common in east- 
ern and central America; Europe. 
F1f _ 52! Family 4. LYNCEIDAE. 

B0 ' m (H O B £fc£j' o *' rt * Second antennae small, each branch of 

' antenna" J" 1 :!,' en In eaCQ consisting of 3 segments; pigment spot 

M<: " (accessory eye) very large; intestine bent or 

coiled and usually without liver sacs; the largest cladoceran family, 
containing about 20 genera. 

Key to the genera of Lynceidae here described: 

a, Intestine not colled or bent 1. Bubyckbcub 

a, Intestine coiled. 

6, A dorsal keel on head 2. ACBoraairs 

6, No keel. 

<h Body oval or elongate. 
d, Outer margin of poet-abdomen concave in outline ; second antennae 

with 7 long setae 3. Guftolebxsis 

<i, Outer margin of post-abdomen straight. 

e, Terminal claw of abdomen with 1 basal spine 4. Aloha 

a, Two basal spines present 6. Pleuboxus 

c, Bod; globular ; animals minute 6. Ghthobds 

1. EuKYOKBOiTS Baird. Body large and oval with snort antennae; 
intestine bent like an S and with liver sacs: 1 species. 

E. Iamellfttua (0. F. Miiller) (Fig. 522). Body very large, being 
sometimes 3 mm long; hinder side of the abdomen serrate: central 
states; Europe. 

2. Aokofebttb Baird. Body minute, elon- 
gate, with a long, broad abdomen ; bead and 
back with a keel; shell with diagonal mark- 
ings; intestine coiled: 3 species. 

A. haxpae Baird (Fig. 523). Body truncate 
behind; length .7 mm.: widely distributed over 
eastern and central America; Europe; common. 

3. OraPTOLebxbib Sars. Body minute, elongate; posterior margin 
straight; second antennae with 7 long setae: 1 species. 

Tatu* (SHow. F. Dent). 


l (Fischer) (Fig. 524). Length .7 mm.; shell reticu- 
late: eastern and central America; Europe. 

4. Aloha Baird. Body minute, more or less oval or rectangular 
in form, with email antennae, the second having 8 setae; with a coiled 
intestine: numerous species, which are very variable in form. 

A. quadrangularis (0. F. Miiller) (Fig. 525). Body oval or quad- 
rangular; pigment spot smaller than eye, abdomen very broad and short; 

^WBW 8 **"*"""^ 

-....-. Fix. 624 

Fig. 623— Acroperui karpae (Herrlck). Fig. B24 — OravtaltberU teetumnario (80m 
F. Dent). Fig. 526— Atona quadrant/alaris (SDaaw. F. Deut). 

shell smooth and yellowish in color; length .9 mm.: widely distributed 
over eastern and central America; Europe. 

6. Fisraoxm Baird. Front end of head long and pointed, forming 
a beak; shell with an arched dorsal edge; intestine coiled: numerous 

P. procnrvna Birge (Fig. 526). Hinder margin of shell denticulate; 
beak curved upwards, forming a hook; length J5 mm.: eastern and 
central America. 

9. Chtdo»d8 Leach. Body minute, spherical, with a long curved 
beak; antennae short; intestine coiled: 8 species. 

! (0. F. Miiller) (Fig. 527). Shell reticulated; pigment 
spot almost as large as the eye; color yellowish; length .4 mm.: widely 
distributed over eastern and central America; Europe. 
Carapace not enclosing the legs and abdomen, and serving only as 
a brood sac; 4 pairs of legs wbich lack the flattened respiratory pro- 
jections of other Phyltopoda; abdomen slender, with 2 long caudal 
spines; bead very large, with, a single. large eye and large second anten- 
na«x 4. genera. 



Fig. 529 

Fig. 530 

Fig. 529 — Evadne nordmanni (Sharpe). 

A, female ; B, male. 
Fig. 530 — Podon leuokarti (Sbarpe). 

Key to the genera of Polyphemidae here described : 

Ox Fresh-water animals 1. Polyphemus 

a, Marine animals 2. Evadne 

&! Head and thorax continuous dorsally. 

6, Head and thorax separated by a notch 3. Podon 

1. Polyphemus 0. F. MiUler. 
Head separated from thorax by a 
dorsal depression: 2 species. 

P. pediculus (L.) (Fig. 528). 
Length 1 mm.; body highly colored 
but transparent : usually in deep lakes 
and rivers; a back-swimmer; widely 
distributed throughout America and 

2. Evadhe Loven. Head and 
thorax not separated by a dorsal depression; brood sac very high; 
antennae small: 3 species; marine. 

E. nordmanni Lov. (Fig. 529). Outer branch of third pair of legs 
with a single spine; length 1.15 mm. or less; colorless: very common 
along the Atlantic coast. 

3. Podon Lilljeborg. Head and thorax separated by a dorsal depres- 
sion: several species; marine. 

P. leuckarti (Sars) (Fig. 
530). Length 1 mm.; both 
branches of the second an- 
tennae with 6 bristles each: 
common along the Atlantic 
coast occurring with the pre- 
ceding; Europe. 


Shell rudimentary and not covering the 
legs or the long, segmented abdomen; 6 
pairs of cylindrical legs, the first pair 
being much larger than the others; 2 ter- 
minal claws on the abdomen: 1 genus. 

Leptodoka Lilljeborg. With the 
characters mentioned above: 1 species. 

L. hyalina Lillj. (Fig. 531). Body elongate; first antennae small 
in female, but very long in male; length 9 mm.; transparent: in clear 
fresh-water lakes in America and Europe; it comes to the surface usually 
only on dark nights,, 

Fig. 531 — Leptodora 
KifaUna. 1, first anten- 
na; 2. second antenna; 
3, shell. 


Order 2. COPEPODA.* 

Body elongated, the thorax and abdomen being usually distinctly 
segmented, and made up of 15 somites, 5 of which are united to form the 
head and 5 form each the thorax and the abdomen. The head and thorax 
together form the cephalothorax. In many forms fusion takes place 
between the head and the first thoracic somite, or between the fourth 
and the fifth thoracic somites, so that but 4 free thoracic segments are then 
present. The abdominal somites are also often united in the female, the 
first and second invariably. The last abdominal segment ends with 
the f urea, a pair of terminal projections bearing a definite number of long 
caudal bristles. In the parasitic copepods the form and structure of the 
body have often been profoundly changed, and all semblance to the typical 
copepod form may have been lost. Ten paire of appendages are present, 
5 of which are cephalic and 5 thoracic. The first pair of antennae 
is uniramose and is longer than the second and may be used for locomo- 
tion; in the male either one or both of the first pair are often modified 
to form clasping organs. The second pair is biramose (but occasionally 
uniramose) and sometimes provided with prehensile hooks and spines. 
A poisonous sting is present in front of the mouth in Argulus. The 
thoracic appendages are biramose swimming legs (Fig. 542,6), which are 
without gills. Except in the Pontellidae and the Argulidae a single 
median eye is present. 

The genital openings are in the first abdominal segment: except in 
the Argulidae the female carries her eggs in 1 or 2 gelatinous masses, 
the so-called egg sacs, which project from the segment into the water. 
The young animal is born as a nauplius. 

More than 2,200 species of copepods are known, of which nine-tenths 
are marine. About half of these are non-parasitic and form one of the 
most important elements in the plankton, because of their enormous 
numbers: they are among the most important scavengers of the sea 
and form besides the principal food of herrings and many other fishes. 
The parasitic copepods are called fish lice and live on the external surface 
and gills of fishes and occasionally on squids and other animals. The 
order contains about 20 families grouped in 2 suborders. 

• See "Die freUebenden Copepoden," etc., by C. Clans, 1863. "Dentschlandg 
freilebende Sttsswasser Copepoden/' by O. Schmeil, Bibllotheca Zoologica, 1892-1896. 
"Synopsis of tbe Bntomostraca of Minnesota," etc., by C. I* Herrlck, Sec. Rep. of 
8tate Zool. v 1895. "Copepoda of tbe Woods Hole Region," by W. M. Wheeler, Bull. 
U. S. Fish. Com. for 1899, Vol. 19, p. 157. "Freshwater Copepoda of Mass.," by 
A. S. Pearse, Am. Nat., Vol. 40, p. 241, 1906. "Notes on Marine Copepoda of R. I./* 
by L. W. Williams, Am. Nat, Vol. 40, p. 639, 1906. "Sttsswasserfauna Deutschl.," 
Heft 11. 1909. "Notes on tbe Marine Copepoda and Cladocera of Woods Hole," etc., 
by B. W. Sharpe, Proc. U. 8. Nat Mas., Vol. 38, p. 405, 1911. 


Key to the suborders of Copepoda: 

Ox The female carries egg sacs 1. Eucopepoda 

o, No egg sacs present 2. Bbanchiuba 

Suborder 1. EUCOPEPODA. 

Body elongate; month parts biting in the free and sacking in most 

of the parasitic forms: 15 families. 

Key to the families of Eucopepoda here described : 
Oa Free-swimming forms (with a few exceptions). 
©t First antennae 17 to 25- jointed, being very long, usually as long as the 
body; but 1 egg sac 

d First antennae prehensile in male ; animals marine 1. Calatodae 

c a Right first antenna prehensile ; marine and fresh-water animals. 

4t First pair of legs normal ; but 1 eye present 2. Centbopagidae 

d t First pair of legs weak or rudimentary ; 3 eyes usually present 


o, First antennae not more than 17- jointed ; usually 2 egg sacs. 
c x Abdomen markedly narrower than thorax; 2 egg sacs; mostly fresh- 
water animals 4. Cyclopidae 

c, Abdomen not markedly narrower than thorax 5. Harpacticidab 

a, Parasitic forms, but which may usually be free-swimming at times. 
o t Segmentation distinct. 
d Body with the usual number of segments ; first antennae 5 to 7- jointed. 

Or Segmentation indistinct and irregular. 6 * H* * 81 " ** 

dt Body wide and flat 7. Caligidae 

d, Body elongate 8. Dichelesthdae 

o, Segmentation wanting or indistinct in the egg-bearing female. 

d Legs rudimentary ; proboscis present ; body worm-like 9. Lebnjodax 

o t Legs rudimentary or wanting; no proboscis present; body worm- 
like 10. Chondbaoanthidax 

c, Legs wanting ; proboscis present ; body thick and sac-like. 


Family 1. CALANIDAE. # 

Body elongate; first antennae very long, with 

23 to 25 joints, in the male but slightly modified; 

second antennae large and biramose; first 4 pairs 

of legs biramose, outer branch 3- jointed ; fifth pair 

A H * ^~^ either like the preceding or modified and unlike 

on the two sides; heart present; a single egg sac 

present : 26 genera, and over 100 species, all marine. 
mSXS^cSiSSRX *• Oalaotb Leach. Thorax composed of 

b^U^Kd of m flrtn either 4 or 5 segments, the last one being some- 
pair of legs. times asymmetrical ; first antennae 25 jointed in 

the female: many species. 
0. finmarchicufl (Onnnerus). Brit (Fig. 532). Length about 4 mm.; 
color yellowish or reddish, but sometimes absent; thorax of 5 segments; 
fifth pair of legs biramose; first antennae as long as the body: New Eng- 

• See "Copepoda," by W. Giesbrecht and O. Schmell, Das Tierrdch, 1898. 


land coast, a widely spread, pelagic species, sometimes so abundant that 
the sea is colored yellow or red, and of great economic importance 
because it forms an important source of food of herring and mackerel, 
as well as of the Greenland whale. 

0. minor Clans. Length about 1.8 mm.; thorax of 4 segments; fifth 
pair of legs biramose; 
first antennae not as long 
aa the body: Gulf stream, 
off New England, a wide- 
ly spread species. 


Oiesbrecht. Thorax of 
female consists of 3 seg- 
ments, the first somite 
being fused with the 

head, and the fourth with 

... »*... -. >. . ** ° 33 — Catocaianua pnco (Wheeler). 

the fifth somite; abdo- 
men of female of 2 or 3 segments; abdomen of male of 5 segments; 
caudal spines very long and plumose: 3 species. 

0. pavo (Dana) (Fig. 533). Abdomen of female of 2 segments; 
caudal bristles symmetrical, branched, and spreading; length 1 mm.; 
body transparent and reddish : a tropical species which may be found in 
the Gulf stream off New England. 

Body elongate; first antennae very long, with 23 to 25 joints in the 
female; the right one (sometimes the left) in the male being prehensile; 
second antennae large and biramose; heart present; first 4 pairs of legs 
biramose, the outer branch being 3-jointed, the inner branch 1 to 3- 
jointed; fifth pair of legs biramose, often modified for elasping; a single 
egg sac present : about 25 genera and 200 species ; in salt and fresh water. 

Key to the genera of Centropagidae here described : 
a. Marine animals, 
b, First antennae with 24 segments. 

c, Thorax of 5 segments 1. Cextiiopaqks 

c, Thorax of 4 segments 2. Tekou 

6, First antennae with 23 segments 3. MmtlDIA 

a, Both marine and fresh-water animals. 
6, First antennae with 26 segments ; fifth feet biramose. . . .4. Limnocalanuh 

6, First antennae with 24 segments : fifth feet uniramose S. Eubtteuoba 

a, Fresh-water animals : first antennae with 2- r i segments. 

B, Fifth feet unirsmose ; abdomen asymmetrical 6. EpischUra 

b, Fifth feet biramose ; inner branch of first pair of feet 2 jointed. 


• See "The North American Centropagidae," etc., by F. W. Bebscht, Bull, of I1L 
Bt Lab., Vol. 0, p. 220, 18B8. 



Fig. 534 

typicuB — 

dorsal aspect 

of female 


1. Oevtbopaoeb Kroyer. Thorax of 5 segments; abdomen of male 
of 5, of female of 4 segments; first antennae with 24 segments; the 2 

branches of all 5 pairs of legs 3-jointed: 13 species; 

0. typictui Kr. (Fig. 534). Fifth thoracic segment 
with 2 lateral projections; first abdominal segment of 
female with 4 thorn-like bristles; length 2 mm.; color 
reddish or bluish, translucent: coast of New England; 

2. Texoba Baird. Furca long and slender; f ureal 
bristles short ; thorax of 4 segments ; abdomen of male of 
5, of female of 3 segments; first antennae with 24 seg- 
ments ; the 2 branches of the 5 pairs of legs 2 to 4-jointed : 
5 species; marine. 

T. longicornis (O. F. Miiller) 
(Fig. 535). Length 1.5 mm.: 
Woods Hole; very common, especially in the 
winter; Europe. 

3. Metridia Boeck. Thorax of 4 seg- 
ments, abdomen of male with 3 segments; first 
antennae with 23 segments; the 2 branches of 
the first 4 pairs of legs 3-jointed; of the fifth 
pair 2 to 4-jointed in female and 5-jointed in 
the male: 10 species; marine. 

M. lucens Boeck (M. hibernica Brady and 
Robertson) (Fig. 536). Length 2.5 mm.: New 

England coast; Europe. 


G. O. Sars. Thorax of 5 segments ; abdomen in 
female with either 3 or 4 segments, in male 
with 5; body slender; furca very long; first 
antennae 25- jointed; all the legs biramose, both 
branches 3-jointed, except the outer branch of 
male, which may be 2-jointed: 3 species; in 
fresh and salt water. 

L. macruruB G. O. Sars. Right outer 
branch of fifth foot in male indistinctly 3- 
jointed with a hook-like process on second 
segment; length 2 mm.; color hyaline: cosmo- 
politan; often common in deep lakes; Europe. 
5. EmtYTEXOBA Giesbrecht. Thorax of 5 segments; abdomen of 
male with 5, of female with 3 segments; first antennae about as long as 

Fig. 536— Metridia lu- 
cens (Wheeler). A, dor- 
sal aspect of male; B, 
fifth pair of legs of male : 
C. fifth pair of legs of 

Fig. 535 — Temora lon- 
gicomis (Wheeler). A, 
dorsal aspect of female ; 
B, fifth pair of legs of fe- 
male : C, fifth pair of legs 
of male. 


I fresh, 

the thorax and 24-jointed; fifth feet uniramoso: 7 species; 
brackish, and salt water. 

E. hirandoides (Nordquist) (Fig. 537). Last thoracic segment of 
female with 2 large projections; length 1.16 nun.; transparent, with yel- 
low bands: Gulf of Mexico and its estuaries, abundant; 
Boston and Narragansett Bays; Europe. 

6. Epxbobtoa Forbes. Thorax of 5 segments; abdo- 
men 4 jointed in female, in male 5-jointed, asymmetrical 
and with prehensile processes on right side; first 4 pairs 
of legs biramose, the outer branch 3-jointed, the inner 
branch 1- jointed; fifth pair nniramose, prehensile in male: 
3 species; in fresh water. 

E. lacnstris Forbes. Length 1.7 mm.; second ab- 
dominal segment as long as the rest of the abdomen: in B^iemoni 
deep lakes; central and western America. *(£SrStk** 

7. DlAPTOWTB* Westwood. Thorax usually of 5 seg- 
ments; abdomen of male with 4, female with 3 segments; first antennae 
with 25 joints; inner branch of first pair of legs 2- join ted, outer branch 
3-jointed; both branches of legs 2 to 4 are 3-jointed; fifth pair irregular 
in form, the inner branch being often rudimentary, the outer branch 
usually 4- jointed in the female, and 5-jointed in the male: about 80 
species, of which 34 are American ; in fresh water. 

D. oregonensis Lilljeborg (Fig. 538). Body small, 1.5 nun. long; 
first abdominal segment of female expanded and equal in length to rest 

* Bm "The North Am. Spedes of Dlaptomoa," by F. W. Schacbt, Ball. III. St. Lab., 
Vol. B, p. 97, 189T. "A revision of the North Am. Speclee of Dlmptomui," bj C. D, 
Marsh, Tram. Win. Acad. Scl., Vol. 15, p. 381. 1U07. 



of abdomen; cephalothorax widest in the middle: widely distributed and 
common over the entire northern part of the country. 

D. laptoptUI Forbes (Fig. 539). First antennae about as long as the 
body; thorax of 4 segments; length 1.5 mm.; body transparent, with pur- 
ple bands, especially on the terminal portion of the antennae and the 
abdomen: common in the central states. 

D. sanguineus Forbes. Body bright red and 2 mm. long; last tho- 
racic segments with strong lateral spines, and a dorsal hump; first 
abdominal segment with strong lateral spines: central and eastern United 
States; common; it occurs only in the early spring, in stagnant pools. 

D. minntns Lilljeborg. Body small, 1 mm. long, and slender; thorax 
of 4 segments; antepenultimate joint of first antennae with a long slender 
process; terminal hook of right fifth feet in male broad: common in the 
Great Lakes and widely distributed in northern America; Europe. 

Body elongate, with 4 thoracic segments; first antennae very long, 
the right one in the male being prehensile; second antennae large and 


Fig. 540 Fig. S*l 

Fig. Bin— Tartan** ntacaudatiu (Williams). A, dorsal aspect of female; B, 
abdomen. Fig. 541 — LaMdoctra /tattoo (Wheeler). A, dorsal aspect of female; 
B. nftb leg of male ; C, right fifth leg or female. 

biramose; first pair of legs weak or rudimentary; heart present; median 
eye and also often paired eyes present; but 1 egg sac: 10 genera and 
over 70 species; marine. 

Key to the genera of Pontellidae here described; 

a, First antennae 23-jointed 2. Lunmen* 

n. First antennae 17 jointed. 

o, The 2 branches of the second antennae of equal length 1. Toctanus 

6, These branches of unequal length 3. Acaxtia 

1. ToRTAirns Giesbreeht. First antennae of female 17- jointed ; abdo- 
men of female consists of 2 or 3 and of the male of 5 segments; the 2 



branches of the second antennae of about the same length; 1 large dorsal 
eye present; fifth pair of legs nniramose: several species. 

T. setacaudatus Williams (Fig. 540). Length of female 1.4 ram.; 
thorax of G segments; fifth pair of feet 2- jointed in female and 3- jointed 
in male: Narragansett Bay; common. 

2. LaBTJMOUA Lubbock. Thorax of 4 segments; abdomen of female 
of 2 or 3, of male of 5 segments; first antennae of female of 23 segments; 
eyes present, a dorsal pair and a ventral median eye: about 14 species. 

L. aatin Wheeler (Fig. 541). Length 2 
mm.; body transparent; last thoracic segment 
in male sometimes asymmetrical: Woods Hole; 

3. Aoa&TXA Dana. First antennae of fe- 
male 17- jointed, of uniform thickness through- 
out; thorax of 4 segments; 1 large dorsal eye 
present; abdomen of female of 3 segments; 
outer branch of second antennae much shorter 
than the inner; 18 species. 

A. tons*. Dana. Length 1.3 mm.; body 
transparent: Atlantic and Pacific Oceans; 
ofteii very common; & widely distributed 

Family 4. CTCLOP^>AE.• 

Thorax with 4 free segments, first an- 
tennae usually about two-thirds the length of 
the body, both being modified in the male to 
serve as prehensile organs; second antennae 
short and nniramose; first fonr pairs of feet 
biramons, outer brunch 3 jointed, inner branch 
1 to 3- jointed; fifth pair of feet rudimentary, 
alike in both sexes, rudiments of a sixth pair 
sometimes present; heart absent; 2 egg sacs 
present : about 75 species and 5 genera, mostly 
in fresh water. 

1. OroxoPtf O. F. Hiiller (Fig. 542). Thorax with 4 free segments, 
abdomen with 5 segments in the male and 4 in the female; first antennae 

• See "A Contribution to a Knowledge of North Am. Fresh-Water Cycloplrtne," by 
ft. n. Forbes, Ban. IU. St. Lab., VoL B, 1887. 

t 8m "A Revielou of tho North American Bpeclea of Cyclops," by C. D. Manb, 
Trans. Wis. Acad. Sri., Vol. IS, p. 1067, 1P09. "The Distribution of the Genus 
Cyclops la the Vicinity of Harertord, Pennsylvania," by Reynold A. Spaeth, Proc. 
Acad. Nat. Set, Vol. BO, p. 20, 1814. 

Fig. G42 — Diagram ol 
Cyclops (altered from 
BUbbw. F. Deut.). 1, Brat 
antenna ; 2, aecond anten- 
na ; 3, mandibles : 4, Brat 
mail 11a; S. second maxilla 
(maitlHped) ; 6, 7, 8, 0, 
the first fonr pairs of tho- 
racic legs, each leg; being 
composed of a basal piece, 
the protopodlte, and two 
terminal pieces, tbe exopo- 
dite and endopodlte ; 10, the 
fifth pair of thoracic lega ; 
11, receptacnlnm aemlnls, 
Id tbe Brat abdominal seg- 
ment : 12, abdomen; 13, 


with not more than 17 and second antennae with 4 segments: over 50 
species, about 18 being American, all in fresh water, although some 
species occur also in brackish and even in salt water; many species are 
extremely variable in form. 

Key to the species of Cyclops here described : 

a, First antennae 17-jointed. 
& t First antennae not reaching the hinder border of head segment. .0. vibidib 
o, First antennae reaching beyond this point. 

o x Fifth feet with 2 long plumose terminal bristles G. leuokabti 

c, Fifth feet with 2 smooth terminal bristles G. bicuspidatus 

c, Fifth feet with 3 terminal bristles C. albtousj 

a, First antennae 12- jointed G. serbulatub 

a, First antennae 10 or 11-jointed O. phalebatus 

0. leuckarti Claus (C. edax Forbes) (Fig. 543). Body slender and 
1.3 mm. long; first abdominal segment very long, equaling the other 3; 
first antennae 17-jointed ; fifth feet 2-jointed, the second joint with 2 very 

long bristles, the outer one 

, w^ springing from the middle of 

^i *H*W^ ^S^^ the segment, the first joint also 

J? £ l§HBj/ w rth a bristle : very common 

r \ V .1 *& * ne Great Lakes and in all 

A T Q ' C parts of the country; Europe. 

Flg.543-CifctopaIei*cikart<(Sfl88W.F.Deut). °* ****** Jurine ( Fi ^' 

and variable in color, usually 

greenish; first antennae 17-jointed and very short, hardly reaching the 

hinder border of the head; fifth feet 2-jointed with a very broad basal 

joint, each joint bearing a plumose bristle. This species, which occurs also 

in Europe, is usually the commonest one in small ponds throughout the 

country. It is extremely variable, 

the 2 principal varieties being C. 

viridis var. brevispinosus Herrick, 

which tends to the larger size, and 

C. viridis var. americanus Marsh 

(C. insectus Forbes), the smaller § \ *" *" C 

and more numerous one. 

Fig. 544 — Cyclops viridio (Sflssw. F. Dent.). 

. 0. biCUSpidatUfl Claus (C. A, furca and f ureal bristles ; B, fifth 

foot; C, receptaculum semlnis. 

pulchellm Sars; C. forbesi Her- 
rick) (Fig. 545). Body slender and 1.3 mm. long; first antennae 17- 
jointed; fifth feet 2-jointed, the terminal joint with 2 terminal bristles; 
furca and caudal bristles very long: very common over the entire country, 
in lakes and rivers, being one of the commonest pelagic cyclops in the 
Great Lakes; Europe. 



0. albidus Jurine (C. signatus fierrick) (Fig. 546). Body 1.4 mm. 
long, and banded with blue or green ; first antennae 17- jointed ; fifth feet 
2-jointed, the first joint being longer than broad, the second joint with 3 
terminal bristles: common throughout the country in clear lakes; Europe. 

Fig. 545— Cyclops bicuspidatus (Sflssw. F. Dent). A, furca and f ureal bristles; 
B, fifth foot ; C, receptaculum semlnls. Fig. 546 — Cyclops albidus (Sflssw. F. Deut.). 
A, fifth foot ; B, f area and forcal bristles ; C, receptaculum semlnls. 

0. serrulatus Fischer (Fig. 547). Body 1.4 mm. long, rather opaque; 
first antennae 12-jointed; fifth feet 1-jointed and plate-like, with 3 
terminal bristles: very common everywhere; Europe. 

0. phaleratus Koch (Fig. 548). Body 1.2 mm. long, brown in color 
with blue feet; antennae 10 or 11- jointed and very short, not reaching 
beyond the middle of the head: not common, but generally distributed 
in shallow lakes and stagnant pools; Europe. 

ff^ O 

Fig. 547 


Fig. 548 

Fig. 547 — Cyclops serrulatus (SClssw. F. Dent.). A, fifth foot : B, furca of male ; 
C, receptaculum semlnls. Fig. 548 — Cyclops phaleratus (SUssw. F. Deut.). A, fifth 
foot ; B, receptaculum semlnls ; C, furca and f ureal bristles. 

2. Oithoha Baird. Head terminating with a beak-like process; 
abdomen with 4 or 5 segments; first antennae in part indistinctly jointed 
and with very long bristles; second antennae 2-jointed: marine. 

O. similis Claus. Beak bent down at right angles to head; caudal 
setae not plumose; body .75 mm. long and usually colorless: Woods 
Hole; Narragansett Bay; Europe. 


Minute, elongate copepods with a cylindrical body, the thoracic seg- 
ments not being much larger than the abdominal; first antennae short, 4 



to 10-jointed, in the male modified and prehensile; second antennae usually 

biramose ; fifth pair of feet 1 or 2-jointed and serving as egg support in 

the female; heart absent; usually a single egg sac present: about 30 

genera and 150 species, mostly marine, usually found among vegetation. 

Key to the genera of Harpacticidae here described : 

Oj Fresh-water animals 1. Cahthocamptos 

a, Marine animals. 

b x The outer branch of the first pair of legs much longer than the inner. 

2. Harpacticus 

5, The inner branch longer than the outer 3. Ectinosoica 

1. Oajtthocamptus Westwood (Fig. 549). Thorax of 4 segments; 
head with a rostrum; first antennae with 6 to 9 joints, usually 8 in the 

female; abdomen 5-jointed in the male and 4 in the 
female: mostly in fresh water; about 6 American species. 
0. minutus Claus. Body 1 mm. long; first antennae 
8- jointed; legs 3-jointed in both branches, except the 
fifth leg, which is 2-jointed: eastern and central states; 
common, especially in muddy pools; Europe. 

2. Habpactiots Milne-Edwards. Outer branch of 
the first leg 3-jointed, almost twice as long as the 2-jointed 
inner branch; conical rostrum present; third pair of legs 
with very strong outer branch: 12 species; marine. 

H. chelifer (O. F. Miiller). Length of male 1 mm.; 
first pair of legs with 1 spine, outer branch with 3; inner 
caudal spines longer than the cephalothorax : Atlantic 
coast; Europe. 

3. Eotinosoma Boeck. First antennae 5 to 7- jointed ; 
first pair of legs scarcely smaller than the others and with 

the inner branch longer than the outer; fifth pair of legs 2-jointed: 12 

E. curticorne Boeck. Length .7 mm.; color dark brown; first an- 
tennae very short, 6-jointed : common in Narragansett Bay ; Europe. 

4. Pakategastes G. 0. Sars. First antennae 6 or 7-jointed ; second 
antennae with a 1- jointed outer branch; last pair of legs very large in 
the female, with an expansion on the basal joint. 

P. sph&ricus Claus. Length .35 mm.; color brown: abundant in 
Narragansett Bay; Europe. 

Family 6. EBGASILIDAE.* 

Body more or less cylindrical, somewhat like Cyclops in shape, 
usually well segmented ; first pair of antennae 5 to 7-jointed, second 3 or 

• "North American Parasitic Copepods Belonging to the Family BrgaaMdae," by 
C. B. Wilson, Proc. U. S. Nat Mus., Vol. 39, p. 263, 1911. 

Fig. 549 
Diagram of 
F. Deut.). 


4-jointed and modified to form a pair of large hooks for prehensile pur- 
poses; female carries a pair of long egg sacs and is parasitic, usually on 
the gills of fresh-water fishes: about 10 ge- 
nera and 86 species ; about 15 species known 
in America. 

Ekgabilub von Nordmann. Cephalo- 
tboras pear-shaped, fifth pair of legs rudi- 
mentary: several species. 

E. versicolor C. B. Wilson (Fig. 550). 
Length 1.5 mm. : parasitic on the gills of the 
common bullhead and three kinds of catfish. 

Fault 7. CALIGIDAE.* 
Body wide and flat, the segmentation 
being more or less obliterated and the female 
being larger than the male; first antennae 
short, with 2 to 3 joints; second antennae in 
form of short hooks; mouth parts form a 
suctorial beak; first 4 pairs of legs usually 
biramoae and facilitate rapid swimming; 

fifth pair reduced or 

wanting; 2 long egg 

sacs with the eggs in a single row in each : about 

35 genera and 200 species, which are parasitic 

externally on fishes. 

Key to the genera of Caligidae here described : 

a, A pair of suckers at front end of body . .1. Calious 

a. No suckers present 2. LefeofHTHEIBUb 

1. Caucus 0. F. Miiller. First and fourth 
pairs of legs uniramose, second and third bira- 
mose; body composed of 4 parts, a cephalot borax, 
a thorax, a genital segment, and an abdomen; a 
pair of suckers at the base of the first antennae: 
17 American species. 

O. rapai Milne-Edwards (Fig. 551). Free 
thoracic segment small and narrower than the 
genital segment, which in the female is about 
twice as wide as the abdomen; length of female 
about 6 mm.: the commonest species, occur- 

• See "North Am. Parasitic Copepods Belonging to the Family Callgldae." etc.. bj 
C. a Wilson, Proc O. 8, Nat Una., Vol. 28, p. 470, 1Q0G ; Vol. 81, p. 609, 1S0T ; Vol. 
83, p. 338, 1903. 



Fig. 552 


rue edicardsi 


ring on the cod, flounder, and more than 25 other kinds of marine 

2. Lepeophtheieus von Nordmann. Similar to CaUgus but with 
out the suckers: 12 American species. 

L. edwardsi C. B. Wilson (Fig. 552). End segment 
less than half as long as the genital segment and 
1- jointed; length of female about 7 mm.: on flounders 
and other fish. 


Body usually elongated and flattened, with segmen- 
tation partially obliterated; first antennae delicate and 
usually many-jointed; second antennae in form of long 
hooks; hinder pair of legs usually reduced: about 20 
genera and 60 species, which are parasitic on fishes, 
principally selachians. 

DiOHELESTixm Hermann. First 2 pairs of legs 
small and biramose, third pair broad and plate-like, 
fourth and fifth wanting; first antennae 8-jointed: 3 spe- 
cies, in fresh and salt water. 
D. sturionis Herm. Length 2 cm.: on the gills of sturgeons; Vine- 
yard and Long Island Sounds. 

Family 9. LERNiEIDAE. 

Body very different in form at different periods; during the breeding 
period the animals swim about freely, and the body consists of a large 
cephalothorax, a thorax bearing 4 pairs of biramose legs, and an elongate 
abdomen; after fertilization the female changes into an unsegmented, 
worm-like creature with minute legs and projections at the forward end 
representing the antennae, and with a pair of egg sacs projecting from 
the hinder end; the front end is imbedded in the body of the fish on 
which it lives: about 50 species. 

1. TiKBTffJKA L. The pairs of legs of the swimming individuals close 
together; body of egg-bearing female twisted S-shape, with a pair of 
egg sacs. 

L. branchialis L. Length extended, 4 cm. ; egg sacs convoluted : on 
the gills of the cod and other fishes. 

2. Leeke^niotts Lesson. Legs of the swimming forms much re- 
duced and close together; body of adult female elongated, with long 
egg sacs. 

L. radiata Les. (Fig. 553). Length 4 cm.: on the menhaden; 



Big. 664 

Fig. 663 

Fig. 663 — LemaBnumM 
radiata (Verriil). Fig. 
654 — Chondraoanthu* 
comutuB (Bronn). 


Female without segmentation and with paired blunt projections rep- 
resenting the appendages, with long egg sacs; male very small, seg- 
mented, with 2 paire of legs, and attach themselves to the body of the 
female: about 40 species. 

Oxohdbaoavtkvs Delaroche. Second an- 
tennae form short, stout hooks: about 20 species, 
parasitic on the gills of marine fish. 

0. cornutus (0. F. Miiller) (Fig. 554). Body 
of female elongate, 6 mm. long; length of male 
•3 mm.: on the gills of the Pleuronectidae. 

Family 11. LEBN^OPODIDAE.* 

Body consists of a head and a thorax; an- 
tennae small; first two pairs of legs long and 
forming the organs of attachment; other legs 
wanting; male minute and attached to the body 
of the female; female with 2 thick egg sacs: 
about 60 species. 

IiKHiratopoPA Blainville. Head somewhat smaller than the thorax, 
which is slender and not segmented : about 9 species ; in fresh and salt water. 

L. f ontinalis S. I. Smith. Length of female 4 mm. : on brook trout 

in Maine. 

Suborder 2. BRANCHIURA. 

Parasitic copepods with a flattened body consisting of a disc-like 
eephalothorax, on the dorsal surface of which is a pair of large com- 
pound eyes, with a thorax of 3 free segments, and an unsegmented, 
2-lobed abdomen; antennae small; mouth parts consisting of a pro- 
boscis containing 2 serrate mandibles and 1 pair of slender maxillae; in 
front of the mouth is usually a poisonous sting projecting from a sheath, 
into which it can be withdrawn ; a large sucker usually present on each 
side of the proboscis and just behind it a pair of short uniramose append- 
ages, the suckers and the appendages representing the 2 branches of the 
second maxillae; 4 pairs of large biramose legs; no egg sacs, the eggs 
being deposited on stones and other objects; the animals leave their 
hosts occasionally and swim about freely : 1 family and about 37 species. 

With the characters of the suborder: 1 American genus. 

• See "North Am. Parasitic Copepods of the Family Lerneopodldae," etc., by 
C. B. Wilson, Proc. U. S. Nat. Mus., Vol. 47, p. 565, 1015. 

t See "North Am. Parasitic Copepods of the Family Argulldae," etc, by C. B» 
Wilson, Proc V, 8, Nat Mua,, Vol 25, p. 635, 1903, 


AaeULVt 0. F. Miiller. Suckers and ating present: 27 species, 
parasites on marine and fresh-water fish, usually in the branchial cavity; 
13 American species. 

A. laticauda 8. I. Smith. Carapace elliptical, considerably longer 
than wide and not reaching the abdomen, which is broadly elliptical; 
length 6 mm.: on the eel, flounder, and other marine fishes; common. 

A. catostomi Dana & Herriek. Carapace round, wider than long, 
and reaching the abdomen, which is round and wider than long; length 
12 mm.; color light green: on fresh-water fish, especially the Backer 
(New England). 

A. f undnli Kroyer. Carapace wider than long and not reaching the 
abdomen, which is very long, being 3 times as long as wide; length 5 
mm.: on Fundulus along the Atlantic coast 

A. versicolor C. B. Wilson (Fig. 566). Length 6 mm.; width 45 
mm.; color brilliantly variegated: in gill cavity of pickerel. 

Order a OSTRACODA.* 

Body without segmentation and laterally compressed, and entirely 
enclosed in a bivalved carapace. The two sides of the carapace can 
be closed by a retractor muscle; when 
they open, the appendages are thrust out 
and propel the animal through the water. 
Seven pairs of appendages are present 
(Fig. 556,B). The two pairs of antennae 
are used for both locomotion and orienta- 
tion, the second pair being either biramose 
or nniramose. The mandibles have each a 
large 3 or 4- jointed palp; two pairs of 
maxillae are present, of which the second 
pair are usually leg-like. Two pairs of 
legs follow, the second pair sometimes 
being bent back and apparently of use 
only in keeping dirt out of the shell. The abdomen is short and may end 
in a projection with two terminal claws called the fnrca. The internal 

* "A Monograph of the Marine and Freshwater Ostracoda," by O. 8. Brady, and 
A. M. Norman, Trans. Royal Dublin Boc. Tola. 4 and 5, 1889 and 1896. "Bynopsla of 
Freshwater Ostrscoda," by C. H. Turner. Am. Nat, VoL SS, p. 8TT, 1899. "Sep. on 
the Freshwater Ostracoda of the I.I. 8.," etc., by B. W. Bbarpe, Proc. U. 8. Nat Mm., 
Vol. 29, p. 880, 1903. "Marine Ostracoda of Vineyard Sound and Adjacent Waters," 
by 3. A. Cuinman, Proc. Boat Soc. Nat. Hist, Vol. 32, p. 8G9, 1906. "The Ostracoda 
of the San Diego Region, II, Littoral Forms," by C. Juday, Univ. Csl. Pnb., Vol. 8, p. 
136. 1907. "Die Susswasserfauna Deutacblaods," Heft 11, 1911. "Ostracoda," by 
a. W. MQller, Du TJerrekn, 1813. 


organs are distinguished by their compactness. A heart is usually absent 
A single median eye or a pair of eyes close together is usually present, 
but the Cyprujlinidae have an additional pair of large compound eyes. 
Ostracods are unisexual animals, most of which lay eggs which they either 
attach to water plants, as in the case of Cypris, or, as in Cypridina, carry 
between the shells until they hatch. Cypris and certain other genera are par- 
thenogenetic, in certain species no males having yet been discovered. The 
Cypridae and Cytheridae are born as nauplii, in which the bivalved shell 
is already present; the other ostracods are born later than the nauplius 
stage. The Ostracoda live on or near the bottom of both salt and fresh 
water, where they crawl or swim actively about and feed principally on 
small animals. Ifntocythere is parasitic on the crayfish. The order con- 
tains 2 suborders and more than 1,400 species, of which the great majority 
are marine, the Cypridae being the only family which lives, almost exclu- 
sively in fresh water. 

Key to the suborders of Ostracoda: 

Ox Second antennae apparently uniramose 1. Podocopa 

a, Second antennae biramose, one branch large, the other minute ; marine. 

2. Myodocopa 

Suborder 1. PODOCOPA.* 

Second antennae apparently uniramose and bearing sharp bristles, 
which are of use in swimming or walking; heart absent; shell without 
antennal sinus: 2 families; mostly in fresh water. 

Key to the families of Podocopa: 

Ox The 2 pairs of thoracic feet dissimilar, second pair bent back. . . .1. Cypridae 
a* The 2 pairs of thoracic feet and the second maxillae all locomotor? and 

similar 2. Cytheridae 

Family 1. CYPBIDAE. 

Shell thin; first antennae 8-jointed, but appearing 6 or 7-jointed, and 
with long bristles; second antennae apparently uniramose, the exopodite 
being a minute plate with 3 bristles, and leg-shaped and 3 to 6- jointed, 
with several long natatory bristles on the second and also the last 
joint; usually a single eye present; manibular palp 4-jointed; first max- 
illa with a 2-jointed palp ; second maxilla small, with a short palp, which 
is prehensile in the male; first pair of legs locomotory, the second bent 
back and not locomotory; abdomen with a furca; genital organs large, 
extending into the space between the shells: about 350 species, mostly 
in fresh water. 

• See "Contributions," etc, by EL W. Sbarpe, Bull. 111. St. Lab., Vol. 4, 1897. 


Key to the genera of Cypridae here described : 
a, Second antennae with natatory bmtlefl- 
b, Animals in fresh water. 
o, Second foot terminates with 1 long straight and 1 abort carved bristle. 

d. Caudal furca long, each side with 2 terminal bristles 1. Citeis 

d, Caudal furca rudimentary 2. Ctpbtdomis 

c, Second foot terminates with 2 straight bristles 3. Cypbia 

6, Animals marine 5. Pontoctpsis 

O) Second antennae without natatory bristles ; animals cannot swim. 

4. Oaxdoka 

1. Ctpbib 0. F. Miiller. Eye single, median; second antennae 

o jointed, the 5 natatory bristles extending to the tip of the terminal 


Fig. 1*58 — Cvprit virtma (8Umw. F. Deut.). A, left sbell; B, diagram allowing 
organs. 1, eje: 2, flrst antenna ; 3, second antenna ; 4. mandible ; G, flrst maillla ; 
8, «econd msillla ; 7, first leg ; 8, second leg ; 9, liver; 10, abdomen ; 11, OTSry ; 12, 
anus; 13, Intestine. 

bristles; first maxilla with a large and second maxilla with a small 
branchial plate; parthenogenetic, the males being unknown: about 8 
American species. 

0. Tirana (Jnrine) (Fig. 656). Length 1.69 mm.; height .95 mm; 
breadth .9 mm. ; shell highest just back of the eye and covered with short 

Fig. BST Fig. sea Fig. sue. 

Pig. SET — Cuprlt fuirata (flliiw. P. Dent.). Fig. BBS — Cyprtdontt vidua (SJflssw. F. 

DeoL). Fig. 689 — Cj/prto ejcipla (Bharpe). 

hairs; dorsal side bluish black; lateral sides greenish with yellowish 
areas extending diagonally downwards from the region of the eye: cosmo- 

0. fuscata Jnrine (Fig. 557). Length 1.5 mm.; height .9 mm.; 
breadth .7 mm.; shell reniform and greenish-brown in color with pellucid 
spots and a bluish-black patch on either side: cosmopolitan. 


2. Otprzdofbzs Brady. Eye single, median; second antennae 
6- jointed, the natatory bristles extending beyond the terminal bristles; 
caudal furca rudimentary; males unknown: 11 species, 3 American. 

0. vidua O. F. Miiller (Fig. 558). Length .6 mm.; height .34 mm.; 
width .4 mm. ; color yellowish-green with 3 transverse bands on the back 
and sides: common everywhere in fresh water; a scavenger. 

3. Otpbia Zenker. Body compressed; eye single, median; second 
antennae 5-jointed, the 5 natatory bristles very long, extending far 
beyond the terminal bristles; furca normal, stout: 11 species, 7 

0. exsculpta Fischer (Fig. 559). Length .58 mm.; height 28 mm.; 
width 26 mm.; shell thin, somewhat transparent and covered with a 
meshwork of longitudinal lines; furca bent: common in shallow ponds 
and slowly flowing, shallow streams; Europe. 

4. Oahdoha Baird. Second antennae of female 
5-jointed and lacking the natatory bristles; furca 
strong: on the bottom, in the mud and sand, not 
being able to swim; 25 species, 9 American. Fig. 560 

0. acuminata Fischer (Fig. 560) . Length 1 mm. ; c j8ffiE iffiSSt)? 
height .44 mm.; width .36 mm.; shell pointed 
behind, white or brown in color; the shorter bristle of the last seg- 
ment of second foot 3 or 4 times as long as the last segment: often 

common; Europe. 

5. Pontoctpris Sara. First antennae 7-jointed 
with bristles longest on the last joint and decreasing 
in length proximally; second antennae with 4 slender 

Fig. 561 Ponto- claws on last joint and a group of 5 bristles on the 

^(Cushman). antepenultimate: several species; marine. 

P. edwardsi Cushman (Fig. 561). Shell somewhat 
triangular with rounded ends, hirsute; first antennae with 4 bristles from 
basal joint; length .85 mm.; height .47 mm.: Eel Pond, Woods Hole, in 

Family 2. CYTHEBIDAE. 

Shell usually calcareous and hard ; eyes paired but more or less con- 
fluent, sometimes wanting; first antennae 5 to 7-jointed, with bristles; 
second antennae leg-like, 4 or 5-jointed, with 2 terminal claws; with a 
basal segment bearing a long flagellnm which contains a duct from a 
poison gland; mandible with palp; first maxilla normal, second maxilla 
leg-like and similar to the 2 pairs of legs; furca rudimentary; animals 
cannot swim: about 700 species and 30 genera, almost exclusively in 
salt water; 8 American marine and 2 fresh-water genera. 


Key to the genera of Cytheridae here described : 

Ox Animals marine. 

b t Dorsal and ventral margins of shell not parallel 1. Loxoconcha 

ft, Margins of shell nearly parallel. 

c, Surface of shell rough 2. Ctthebeis 

c, Surface of shell smooth 3. Pbeudootthebbtta 

a, Fresh-water animals. 

h x Animals free-swimming 4. Limnicytherk 

6, Animals parasitic 5. Entoctthebs 

1. Loxooohoha Sars. Shell with a notch at the dorso-posterior 
angle; ends and ventral margin extended into a flattened rim; first 
antennae 6-jointed, with a group of slender setae on the last joint; sec- 
ond antennae 4- jointed: 2 American species; marine. 

L. impress* (Baird) (Fig. 562). Length .82 mm.; height .51 mm.: 
Vineyard Sound; very common in shallow water, among eel grass, 
hydroids, etc. 

2. Cythebeis Sars. Shell strongly calcareous; first antennae 5 or 
6-jointed; second antennae 4-jointed, with a short flagellum in the female; 
first pair of feet differing on the two sides of the body in the male : 10 
American species; marine. 

0. arenicola Cushman (Fig. 563). Shell quadrangular, the dorsal 
and ventral margins being almost parallel, 1 mm. long; .5 mm. high; sur- 
face with irregular patches, usually each with a single hair: common on 
sandy bottoms in Vineyard Sound. 

Fig. 562 Big. 563 Fig. 564 

Fig. 562 — Loxoconcha impre»»a (Cash man). Fig. 563 — Oythereis arenicola (Cash- 
man). Fig. 564— I>*eudocytheretta e&icardrt (Cushman). 

3. Psetoocythebztta Cushman. Inner border of shell irregular; 
flagellum of second antennae 3- jointed; first foot of male with a seta on 
the hinder border; left and right first feet of male very different: 1 

P. edwardsi Cushman (Fig. 564). Dorsal and ventral margins of 
shell nearly parallel, with rounded hairy ends; length 12 mm.; width 
.61 mm. : Vineyard Sound in rather deep water, the commonest ostracod 
of the region. 

4. LntfliOYTHBBK Brady. First antennae 5-jointed with short bris- 
tles on the outer edge; second antennae 4-jointed; mandible with large 
branchial plate: 2 American species, both in Illinois. 



L. reticulata Sharpe (Fig. 565). Length .68 mm.; height .35 mm.; 
breadth 25 mm.; color whitish; shell with conspicuous polygonal 

5* Evtooyteebe* Marshall. First antennae 
6- jointed, with long jointed bristles; second 
antennae 4- jointed ; mandible with branchial plate : 
1 species. 

E. cambaria Marsh. Body oval, .6 mm. long; 
shell thin and smooth: parasitic on gills of 
Cambarus in Wisconsin. 

Suborder 2. MTODOCOPA. 

Fig. 566 — Limnioythere 

reticulata — inside 

of left shell 


Second antennae biramose, one branch being large and many-jointed 
and usually with natatory bristles, the other minute; front margin of 
shell with a deep notch in front for the protrusion of the second an- 
tennae: 5 families, marine. 

Key to the families of Myodocopa here described : 

Ox Eyes present 1. Cyphidintdae 

a. Byes absent 2. Haloctpbidae 


Shell with a deep notch in front (antennal sinus); 3 eyes present; 
first antennae stout, 5 to 8- jointed, bearing the large sense organ ; second 
antennae with outer branch usually 9-jointed; inner branch in male 

3- jointed; mandibular foot 5-jointed, terminating in 
a claw: 2 American genera. 

Samizlla Norman. Shell of female without 
notch; first antennae 5-jointed, with sense organ on 
third joint in male: 2 American species. 

8. zostericola Cushman (Fig. 566). Shell 1.3 
mm. long and .86 mm. high in the male and 1.1 mm. 
long and 1 mm. high in the female, obliquely truncate 
behind : on eel grass and hydroids at Woods Hole. 

Fig. 666 
BarHetta zostericola 
1, antennal sin 



Shell very thin and flexible with notch (antennal sinus) in front, 
above which is a rostrum ; median tentacles present between first antennae ; 
eyes absent: 3 American genera, all on the Pacific coast. 

1. Halooypris Dana. Rostrum very short, notch small; shell short 
and high: 1 American species. 

* See "Bntocythere cambaria, a Parasite Ostracod," by W. S. Marshall, Trans. 

Wis. Acad. 8d. t Vol. 14, pt 1, p. 117. 

t See "Ostracoda of the San Diego Region, I. Halocypridae," by C. Jnday, Univ. 
Cal. Pub., Vol. 3, p. 13, 1906. 


H. pelagica Claus (Fig. 567). Shell 1.4 mm. long and 1.1 mm. 

high ; first antennae strongly curved : Atlantic and Pacific Oceans. 

. 2. OovoHffiOXA Dana. Shell elon- 

gate with well-developed rostrum and 
notch: 7 American species. 

0. magna Claus. Shell subquad- 
rangular, higher behind than in front, 
2.6 mm. long and half as high; dorsal 
margin with a depression near the mid- 
dle: widely distributed in the Atlantic 
(luday)T 1? antennaf VnusI* and Pacific Oceans. 

Order 4. CIRRIPEDIA.* 

Body usually of large size and enclosed in a calcareous shell; animals 
marine and sessile as adults, living either attached to rocks, timbers, or 
seaweed, or as parasites on or in the bodies of crabs, mollusks, or other 
marine animals. A cement gland in the penultimate joint of each anterior 
antenna furnishes a secretion by means of which the barnacles are attached ; 
the parasitic Rhizocephala fasten themselves to their hosts by means of 
long root-like projections of the head. The body, like that of the 
Ostracoda, is entirely enclosed in a carapace which arises on the back of 
the head and thorax and falls in a right and left fold over the body, form- 
ing the characteristic shell. The appendages are a pair of mandibles, two 
pairs of maxillae, and six pairs of biramose and plumose thoracic append- 
ages or legs. It is these legs which project from the shell and give the 
animal its characteristic appearance. In some of the parasitic cirripeds the 
number of pairs of thoracic legs is less than 6 and in the Rhizocephala 
both they and the mouth parts are altogether wanting. The abdomen is 
rudimentary. The digestive tract in the barnacles passes straight to the 
anus at the hinder end of the abdomen ; in the Rhizocephala no digestive 
tract is present, the nutriment being absorbed through root-like projections 
of the stalk which entwine the viscera of the crab on which the parasite 
is living. 

With a few exceptions all cirripeds are hermaphroditic, a condition 
which is undoubtedly correlated with their sessile habit of life. In a 
few genera of barnacles (Ibla, Scalp ellum) complementary males also 
occur, which live in or near the genital openings of the hermaphroditic 
individuals. Scalpellum ornatum, Ibla cummingi, and all the species of 
the genera Cryptophialus and Alcippe, which burrow in the shell of 

• See "A Monograph of the Subclass Clrrlpedia," by Charles Darwin, 1851-1854. 
"The Barnacles (Clrrlpedia) Contained In the Collections of the U. 8. National 
Museum," by H. A. Pllsbry, Ball. 60, U. 8. Nat Mus. t 1907. 


snails, fere unisexual, the male being a minute animal, consisting of little 
but genital organs, which lives a parasitic life on the body of the female. 
Cirripeds are born as nauplii and pass through a later larval stage pos- 
sessing a bivalve shell, a pair of compound and a simple eye, called the 
cypris stage, during which they attach themselves. 

History.— The thick, calcareous shells of barnacles have always made 
them conspicuous objects, and they have been well-known animals for a 
very long time. The medieval zoologists supposed the Lepadidae to be 
the young of bernicle geese, which often appear in large flocks along 
the seashore of Europe, and this belief led them to call the animals goose 
barnacles. It was not until the beginning of the eighteenth century 
that this belief disappeared. The cirripeds were usually classified with 
the mollusks by the earlier zoologists, although Lamarck in 1802 placed 
them among the crustaceans, until J. V. Thompson in 1830 showed the 
barnacle larva to be a nauplius and thus definitely proved their crus- 
tacean nature. Cuvier, however, in 1830 still placed them among the 

About 500 species of Cirripedia are known, of which about 15 species 
occur on our Atlantic coast. The order contains 5 suborders. 

Key to the suborders of Cirripedia here described : 

Ox Body enclosed in a calcareous shell ; barnacles 1. Thoracica 

a, Body without a calcareous shell ; animals parasitic. 

&i Thoracic appendages present; animals bore into the shells of mollusks 

and cirripeds 2. Abdominalia 

h t Thoracic appendages wanting; parasitic on decapods. . . .3. Rhizocephala 

Suborder 1. THORACICA. 

Barnacles. Body enclosed in a calcareous shell and attached at the 
dorsal side of the head, the 6 pairs of biramose, tendril-like thoracic legs 
being thrust out as the shell opens to gather in the small animals and 
organic fragments which form the food: about 4 families. 

Key to the families of Thoracica: 

Oi Body attached by a long, thick stalk, 
bi Stalk almost or quite as wide as the rest of the body, and scaly. 


ft, Stalk much narrower than body 2. Lepadidae 

a. No stalk present. 

6, On rocks, timbers, etc 3. Balanidae 

ft, On whales 4. Coronuudae 

Family. 1. MITELLIDAE. 

Stalk with scales or spines and as wide as the rest of the body, or 
nearly so; shell consists of a large number (18 or more) of pieces; 
mostly hermaphroditic, Scalpellum ornatum on the South African coast 


and Ibla cummingi in the Philippines, however, being unisexual with com- 
plementary males, and Scalpeilum vulgare of the European seas hermaph- 
rodite also with complementary males; Lithotrya 
bores into rooks and mollusk shells and coral : 
about 10 species. 

1. Mitella Oken [Pollicipes Leach) (Fig. 568). 
Shell consists of from 18 to over 100 pieces, of which 
the carina, the terga, and the acuta are the largest; 
hermaphroditic: 8 species. 

H. polymerua (Sowerby). Shell composed of 

upwards of 180 pieces arranged in several whorls, 

decreasing in size from above downwards; total length 

7 cm.: west coast of America; common. 

2. SoAXPZLLint Leach (Fig. 560). Stalk thick, short, 
and usually scaly; shell composed of 12 to 15 pieces; 
either unisexual or hermaphroditic, with complementary 
males: 140 species; mostly in deep water. 

B. strcami Sara. Stalk about half as long as body 
and covered with imbricated scales; total length 12 mm.: 
in deep water in the gulf of Maine, and to the northward ; 

Family 2. LEPADIDAE. 

Stalk much narrower than the rest of the body and without scales; 

body flattened and usually covered with a shell consisting of 5 pieces, 
a pair of large scuta at the stalk end of the body, a 
pair of smaller terga at the opposite end and a, 
median dorsal carina which lies along the hinge, the 
shell opening and the legs protruding on the ventral 
side; Anelaama, which lives parasitically in the skin 
of dogfish in the North Sea, is without a shell; 
hermaphroditic, without complementary males : about 
7 genera and 30 species, which attach themselves 
usually to floating objects. 

1. Letab L. Goose barnacles (Fig. 570). 
Scuta broad and triangular; terga and carina well 
developed, the latter reaching posteriorly between 
the former and all 5 parts of the shell abutting on 

one another: about 6 species, 5 American,- all of which are found on both 


L. fascicularis Ellis and Solander. Stalk short, not as long as the 

body; plates thin and paper-like; carina bent at right angles; length 

Fig. 670. 


Lrpat anatifera 


1, scutum ; 2, tergnm 


of shell 4 cm.; cosmopolitan, often very numerous, especially in early 
summer, on the North American coast, sometimes as far north as the 
Bay of Fundy, attached to seaweed and other floating objects; Pacific 
coast north of San Francisco. 

L. anserifera L. Stalk about as long as the body; plates radially 
grooved; length of shell 5 cm.: cosmopolitan. 

L. anatifer* L. (Fig. 570). Stalk usually as long as 
or longer than the body; shell bluish-white; plates faintly 
striated; length of shell 5 cm. or less: cosmopolitan; on 
ships' bottoms and floating objects; the commonest species; 
more southerly than L. fasdcularis. 

2. Cohchodekxa Olfers. Carina and terga small or 
wanting; scuta narrow, the parts of the shell not touching 
one another; stalk long and almost as broad as the body, 
tapering from it to the point of attachment: usually conJfco&erM* 
attached to ships' bottoms, but also to other objects; 3 (Ptfsbry). 

0. virgatum (Spengler) (Fig. 571). Length, including stalk, 5 cm.; 
color grayish, with 6 dark longitudinal bands: cosmopolitan. 

Family 3. BALANIDAE. 
Rock barnacles. No stalk present; body enclosed in a thick cal- 
careous shell; this is made np of a number of pieces which are joined 
together to form a cylinder, in which the animal lies on its hack with 
the fl paire of thoracic feet uppermost; 2 pairs of hinged plates, cor- 
responding to the scuta 
and terga of Lepas, 
close the aperture of the 
' cylinder and, on open- 

' ing, permit the legs to 
be thrust out and sweep 
/ in particles of food: 

incrusted on rocks and 
timbers, etc, often in 
great numbers; about 7 
genera and 75 species. 
BaLAWS L. (Fig. 
572). Cylindrical shell composed of 6 thick pieces joined by thinner ones; 
basis of the shell either membranous or calcareous: about 46 species, of 
which 8 occur on the Atlantic coast. 

B. balanoidex (L.). The common barnacle. Base of shell mem- 
branous; tergum with a spur; cylindrical shell of variable shape and 


with longitudinal ridges; length up to 5 cm.: North Atlantic coast, 
extremely common between tide lines. 

B. eburneus Gould. Ivory barnacle. Shell low and broad in form 
and with a smooth, white exterior; base of shell calcareous: common 
from Massachusetts Bay to the West Indies, chiefly below low-water 
mark; often in brackish and even fresh water. 

B. crenatus Bruguiere. Shell white, up to 34 mm. high and 19 mm. 
wide; base calcareous and very thin: Atlantic coast, on stones and 
shells in deeper water, also on ships. 

B. tintinnabulum (L.). Shell often ribbed longitudinally, reddish 
or bluish in color with a calcareous base; up to 6 cm. in diameter and 
in length: cosmopolitan, in the warmer seas, often brought to our coast 
on the bottoms of vessels; is eaten in many countries. 


Similar to the preceding family but differing in that the terga and 
scuta, although freely movable, are not hinged with one another; base 
of shell membranous: on Cetacea; 4 genera and 7 species. 

Oobovula Lamarck. Shell formed of 6 principal pieces and wider 
than high; terga and scuta much smaller than the opening: 3 species, 
on whales. 

0. diariema L. Shell crown-shaped, scuta present, terga very small 
or wanting: off the New England coast. 

Suborder 2. ABDOMINALIA. 

Body segmented, surrounded by a voluminous mantle but without 

a shell, and with only 3 pairs of feet on the hinder part of the thorax; 

unisexual; the animal bores into the shells of mollusks and cirripeds: 2 



Stalk weak and with a large chitinous disc of attachment; legs 
uniramose; mantle opens on the side; males minute, without legs, 
attached to the females: 1 genus. 

Alcipfe Hancock. With the above-mentioned characters : 1 species. 

A. lampas Hancock. Length 6 mm.; bores in dead Natica shells 
which are inhabited by hermit crabs: Woods Hole. 

Suborder 3. RHIZOCEPHALA. 

Body without segmentation, appendages, or shell and sac-shaped, with 
a stalk composed of branched thread-like projections which extend into 
the body of the host; without intestine; hermaphroditic, with comple- 


mentary males: 2 families with about 6 genera and 36 species. The best- 
known genera are Saceulina Thompson, with about 6 species, which live 
on decapod crabs, forming a thick sac between the abdomen and thorax, 
and Peltogaster Rathke, with about 7 species, which live on hermit crabs. 
They occur in the North Atlantic off the European coast 

Subclass 2. MALACOSTRACA.* 

Crayfish, lobsters, and crabs, and the other higher and larger crusta- 
ceans. In all, excepting the Phyllocarida, the body is made up of 20 
somites, of which 5 form the head, 8 the thorax, and 7 the abdomen. The 
head is invariably fused with one or more thoracic somites, and together 
with these, in the Phyllocarida and Thoracostraca, is covered by a shield- 
like carapace (Fig. 625,5). The number of pairs of appendages is 
typically 19, of which 5 are cephalic, 8 are thoracic, and 6 are abdominal : 
the last abdominal somite, which is called the telson, bears no appendages. 
The cephalic appendages are the first and second pairs of antennae, one 
pair of mandibles, and two pairs of maxillae. The terminal portion of 
the antenna is called the flagellum (Fig. 576,1): in many cases more 
than one may be present, one of which may be a smaller or so-called 
secondary flagellum. The basal portion of the antenna is called the 
peduncle (Fig. 576,2). Tlie exopodite of the second antenna is broad 
and flat in many forms and is called the antennal scale (Fig. 615, 3). 

From one to five of the anterior pairs of 
thoracic appendages are specially modified to assist 
in eating and are called maxillipeds, while the 
posterior pairs are called periopods and are used 
principally for locomotion (Fig. 576,5). The 
thoracic appendages are often prehensile and used 
for grasping, in which case the distal segments may 
be modified in one of three ways : (1) the terminal 
segment may form with the next one a forceps-like 

pinching claw or chela as in the crayfish or crab, pig. 573 marrams of 

when the appendage is spoken of as chelate (Fig. TZ^^J?^: 
573, B); (2) the terminal segment may simply JSSti^ ch elalectow 
bend back on the next one as in the Amphipoda, 

when the appendage is spoken of as subchelate (Fig. 573, A); (3) the 
terminal segment may be sharp and spine-like, as in the parasitic isopods. 
The abdominal appendages are called pleopods or swimmerets (Fig. 

• See "Natural History of Economic Crustaceans/' etc., by R. Rathbun, Bull, of 
U. S. Fish Com. for 1889, p. 768. "Higher Crustacea of New York City/' by F. P. 
Paulmeier, Bull. 91 of N. Y. St. Mus., 1905. "Die SUaswasserfauna Deutschlanda," 
Heft 11, 1910. 


579, 4) and have a variety of functions, being locomotor and respiratory 
and often serving for the attachment of the eggs or the young. The 
appendages are all primarily biramose except the anterior antennae, 
although in the adult animal either the exopodite or the endopodite may 
be absent and the appendages thus become uniramose. The eyes are either 
pedunculate or not. The subclass contains 3 divisions and over 11,200 

Key to the divisions of Malacoatraea : 
i*i Abdomen composed of 8 segments ; large carapace present. .1. Phyllocabtoa 
a. Abdomen of 7 segments or leas. 

b, Carapace absent; thorax usually with 7 free segments 2. Abtuhostraca 

6, Carapace present covering a part or all of the thorax 3. Thouacostraca 

Division 1. PHYLLOOARIDA-* 

Primitive Molacostraca with a thorax bearing 8 pairs of leaf-like 
gills, a long abdomen composed of 8 segments bearing 6 pairs of 
appendages and with a large camp-"*" -»*i™«- «■* *•*<•* *>,™.» 
and a portion pf the abdomen ; eyei 
species, all marine, 

Nebalia Leach. Candal 
fork (fnrca) with lateral spines: 
4 species. 

N. bipes (Fabricius) (Fig. 
574). Body slender, compressed, 
10 mm. long; genital opening on 

tbe last thoracic segment in the pi,. BT*-»« D «H a wp« (Packard), 

male and ou the antepenultimate 

segment in the female; eggs carried by the female between the thoracic 
feet: North Atlantic, in shallow water, among seaweeds; Europe. 

Division 2. ABTHBOSTBACA. 
Malacostracans of small but not minute size in which the first 
thoracic somite (in a few cases the second also) is united with the bead, 
the remaining 7 being free and appearing as distinct segments; no 
carapace present ; abdominal somites more or less coalesced, 6 free seg- 
ments usually appearing, although the number is very often smaller; 
appendages well developed, consisting, when all are present, of 2 pairs 
of antennae, 1 pair of mandibles, 2 pairs of maxillae, 1 pair of maxilli- 
peds (belonging to the first thoracic segment which is fused with the 
bead), 7 pairs of periopods and 6 of pleopods; eyes in most cases ses- 

• See "The Order Phylloearida." etc., by A. 8. Packard, Twelfth Ann. Hep. D. 8. 
GeoL Bar. for year 1878, pt. 1, 1883, p. «2. "The Crustacean Nebalia," bj A. 8. 
Packard, Am. Nat., Vol. 16, p. 801. 


sile; the eggs are carried on the ventral surfaee of the thorax in a 
brood pouch formed by flat projections of the thoracic legs and the 
young animals are like the parents in form, there being no metamor- 
phosis: 2 orders. 

Key to the orders of Arthrostrttca: 

Oi Usually laterally compressed; very often jumping animals. . . .1. Amfhifoda 
a* Usually dorsoventrally flattened ; many terrestrial and many parasitic. 

2. Isopoda 

Order 1. AMPHIPODA.* 

Body elongated and usually laterally compressed; first 2 pairs of 
periopods, which are called gnathopods (Fig. 577, 3 and 4), usually 
larger than the others and subchelate, being used for grasping the food ; 
gills on the periopods; hinder 3 pairs of pleopods usually adapted for 
jumping: about 45 families and 2,300 species, which are almost exclu- 
sively marine, many species dwelling on the seabeach, burrowing in the 
sand or living under stones or decaying vegetation; food consisting 
mostly of living or dead animals of all kinds, also of decaying vegetable 
matter; a number of species are parasitic; 3 suborders. 

Key to the suborders of Amphipoda: 

Ox Seven free thoracic segments. 

bx Head very large, with very large eyes 1. Htperiidea 

6, Head and eyes not of unusual size 2. Gammaridea 

Hi Six free thoracic segments; abdomen very rudimentary 3. Caprellidea 

Suborder 1. HYPERIIDEA. 

Head and eyes both very large; maxilliped without a palp; 7 pairs 
of thoracic legs present: parasitic or living on or in pelagic animals, 
especially medusae; 4 families. 

Key to the families of Hyperiidea here described : 

Ox Usually found in medusae 1. Hypebiidae 

Of In the tests of Salpa or Pyrosoma 2. Phhonimidajc 

Family 1. HYPEBIIDAE. 

Head large and almost entirely occupied by the enormous eyes; 
5 abdominal segments; mandibular palp present: usually found in large 
medusae; about 8 genera. 

Hyfx&ia Latreille. Gnathopods feeble: several species in Aurelia, 
Cyanea, and other medusae; 2 species on the Atlantic coast. 

H. galba (Montagu). Periopods with very few setae; length 15 
mm. : in Aurelia; coast of New England. 

* See "Synopsis of the Amphipoda/' by S. J. Holmes, Am. Nat., Vol. 37, p. 267, 
1003. "The Amphipoda 1. Gammaridea," by T. R. R. Stebbing, Das Tierreich, 1906. 
"The Amphipoda of Southern New England," by S. J. Holmes, Ball, of U. S. Fish. Corn., 
Vol. 24, p. 457, 1904. "The Freshwater Amphipoda of North America," by Ada L. 
Weckel, Proc. D. 8. Nat Mus., Vol. 32, p. 25, 1907. 


H. medusarum (0. F. Miiller) (Fig. 575). Gnathopods covered 

with setae on the sides; length 12 mm.: found in Cyanea and other 

jellyfish; coast of New England, north of Cape 



. Head very long dorsoventrally, on the sides 

• 1 1 and top of which are the large eyes; no mandibular 

Fig. 576 — Hvperla me- palp present; second antennae rudimentary in the 
dusarum (Leonia). _ , _ t _ 

female: about 7 genera. 

Pkbovtjca Latreille. Fifth pair of periopods with large chelae; 
last thoracic segment elongated: 1 species. 

P. sedentaria (Forskal). Length 3 cm.: cosmopolitan; each indi- 
vidual living in the transparent test of Salpa or Pyrosoma. 

Suborder 2. GAMMARIDEA. 

Seven free thoracic segments and pairs of thoracic legs; mazilli- 

ped with a 2 to 4-jointed palp : about 40 families and over 1,000 species. 

Key to the families of Gammaridea here described : 

<*! Three last abdominal somites normal and not fused together. 
&! Body compressed and not flattened. 
Oj Last pair of pleopods do not end in a hook. 
<fi First antennae usually shorter than second. 
0! First antennae without secondary flagellum. 
f x First antennae much shorter than the second. 

g x Two eyes present 1. Obchestiidae 

g % Four eyes present 3. Aicpeuscidab 

U First antennae but little shorter than second 4. Calliopiidae 

e, First antennae with 2 flagella, posterior periopods very broad. 


d, First antennae usually longer than second, or of nearly the same length. 
Cj Secondary flagellum present; both pairs of gnathopods usually of 

same size 5. Gammajodae 

e, Secondary flagellum usually absent; second pair of gnathopods 

larger than the first 6. Phottdae 

c, Last pair of pleopods end in a hook 7. Amphithoidae 

J, Body flattened, with small abdomen 8. Cobofhiidab 

a, Last 3 abdominal somites fused with caudal stylets 9. Chelubidab 

Family 1. OECHE8TIIDAE. 

The beach fleas. First antennae much shorter than the second; 
mandible without palp; body laterally compressed; second gnathopod 
much larger than the first: about 13 genera and 100 species, which live 
largely on the seashore and are more or less adapted to a terrestrial life. 

Key to the genera of Orchestiidae here described : 

Ox First antennae shorter than peduncle (long basal segments) of second. 

&! Dark-colored animals found on the seabeach 1. Obcbebtia 

6, Whitish animals which burrow in the sand 2. Taiabchestia 

Oi First antennae longer than peduncle of second. - . • .3. Htalella 


1. OaoKKBTiA Leach. Dark-colored amphipoda in which the first 
antennae are shorter than the basal portion (peduncle) of the second, 
and the first gnathopod is subchelate in both sexes: 25 species. 

0. agill* 8. I. Smith (Pig. 576). First antennae not reaching the 
tip of the penultimate joint of peduncle of second antenna; length 14 

Fig. 676— OroAetfls agiU* (Verrul). 

uncle: 8, first gnathopod; 4, second gnat 
T, abdomen; 8, thorai. Fig. 077— Orcheit 
»* in Fig. STB. 

> potmlrtj (PauTmeler)! 

nun.; color brownish; Atlantic coast, under masses of decaying sea- 
weed on the shore, as far south as Florida; when disturbed it hope and 
runs with great rapidity; Europe. 

0. palustris" S. I. Smith (Fig. 577). First antennae reaching 
beyond tip of penultimate joint of peduncle of the second antennae; 
length 18 nun.; color brownish: Cape Cod to New Jersey; on the shore of 
salt marshes; Europe. 

2. Talokohxbtia Dana. Whitish, large am- 
phipoda in which the first antennae are shorter than 
the basal portion (peduncle) of the second and the 
first gnathopods are subchelate in the male and not 
in the female: 20 species. 

T. longicorniaf (Say) (Fig. 578). Eyes large; 
second gnathopods of male very large ; first antennae 
just reaching to the tip of the penultimate joint of 
the second antennae; length 25 mm.; color whitish, 
but sometimes brown: Cape Cod to New Jersey, 
common on sand beaches, burrowing in the sand 
in tbe daytime. 

3. S. I. Smith {AlloTchestes Dana). Small amphipoda 
in which the first antennae are longer than the basal portion (peduncle) 
of the second: 2 species. 

• Bee "The 8elt-Marah Ampblpod, Orcheatla palnstrla," by M. B. Bmallwood, 
Cold Spring Harbor Monographs, III, 1906. 

t Bee "Tbe Beach Flea ; Talorcheitla longlcomls," by M. E. Sinallwood, Cold 
Spring Harbor Monographs, I, 1908. 

meler) . A, second 
anathopod of male ; B, 

first gnathopod of fe- 
male ; C, second gnath- 
opod of same. 


H. dentate (Say) (Fig. 579). Hinder dorsal margin of the first 
and second abdominal segments produced to form spines; length 6 
mm.: in fresh-water ponds in 
the eastern states, where it is 
one of the two common fresh- 
water species of amphipods, 
(lammarus fasiatus being the 


Fig. 5T9— Httahttadmtata (Fanbneler). I, riret M" 61 ™ 6 bn t uttle 

Drat gnathopod : 2, second gnathopod ; 3, nhnrtpr than the uwmil mil 

pcrlopodt; 4. pieopoda ; s, jumping let*. snorcer man coe second ana 

with a secondary fiagellum; 
mandible with a palp; posterior periopods very broad and modified for 
digging: about 8 genera and 22 species. 

Hauitokiub St. Midler. Characters as above; small rostrum 
present: 1 species. 

H. axenarins (Slabber) (Fig. 580). Length 18 mm.; color whitish: 
Georgia to Cape Cod; on the seabeach near 
high- water mark, where it burrows with 
great rapidity; Europe. 


First antennae some distance in front of 
and at least half as long as the second; 4 
eyes usually present; last 2 segments of 
abdomen fused together: a burrowing family with about 3 genera and 
40 species. 

Ajtpelisoa Kroyer. Telson divided by a median cleft; 4 eyes 
present ; first antennae about half as long as the second : about 25 species. 

A. macrocephala Lilljeborg. Postero-Uteral margin of third ab- 
dominal segment elongated; head usually as long as the first 3 thoracic 
segments; length 15 mm.; color white: Vineyard Sound and north- 
wards, living in tubes in the mud; Europe. 

A. compressa Holmes. Head considerably shorter than tbe first 3 
thoracic segments; body very compressed; length 6 mm.: common from 
Cape Cod to Cape Hatteras. 

First and second antennae of nearly the same length; periopods 
rather strongly built, the last 3 pairs increasing successively in length: 
about 15 genera and 30 species. 

AMPH1P0DA 369 

CaxurorroB Lilljeborg. Both pairs of gnathopods large and of 
equal size; terminal abdominal segment slender and not split: 2 species. 

C. leviuscuhu (Kroyer) (Fig. 581). First and second antennae of 
nearly the same length; eyes large; length 16 mm.; color light green: 
Cape Hatteras to Greenland, in tide pools 
and among seaweed; Europe; North Pacific. 

Family 5. GAMMABIDAE. 

Both pairs of antennae long, the first 

antennae usually longer than the second and 

with a secondary flagellum which is a small 

side branch of it; mandible with a palp; 

both pairs of gnathopods usually of the same size; terminal pleopods 
extending beyond the others: over 50 genera and 250 species, largely in 
fresh and brackish waters. 

Key to the genera of Gammaridae here described : 
o, Last 3 abdominal segments with small bunches of hairs along hinder margin. 

b. First 3 abdominal segments not extended behind 1. Gammabub 

6, First 3 abdominal segments eacb extended behind as an acute tooth. 

2. Cabinooaumabtjs 
a. No such bunches of hairs on these segments 3. Elasmofds 

1. OakWAKlTB Fabrieius. Telson deeply cleft; last 3 abdominal seg- 
ments with bunches of small hairs: over 30 species; in salt and fresh 
water; 6 fresh-water species in the United States. 

Fig. 582 Fig. 583 

Fig. 582 — Gummorin locutta (Panlmeler). Fig. 1583 — Ohiuhwik tadatvs (Panlmeler). 

i (L.) (Fig. 582). First antennae longer than the second; 
secondary nagellum with about 8 joints; length 20 mm.; color greenish: 
Arctic Ocean to New Jersey, being very common under stones and in 
seaweed along the seashore; Europe. , 

O. annulatos S. I. Smith. First antennae shorter than the second; 
length 15 mm.; no lateral hairs ou the fourth abdominal segment: Long 
Island Sound to Bay of Fundy, 


0. fasciatns Say (Fig. 583). First and second antennae of about 
the same length; length 15 mm.; color whitish: common in fresh-water 
ponds and streams, it and Hyalella dentata being the common fresh-water 
ampbipods in the eastern states. 

2. Oartnogamjubus Stebbing. Telson deeply cleft; last 3 abdom- 
inal segments with bunches of small hairs and first 3 each with a dorsal 
backwards projecting spine: about 9 species. 

0. mucronatns (Say) (Fig. 584). Antennae of the same length; 
length 15 mm.; color greenish: Cape Cod to Florida, 
algae and in brackish water. 

BTS-C84 11*885 

Fig. 584 — Carinoffatnmam mucronatva (Paulmeler). Pig. BBS — Elusmopu* Ivvto 

3. Elabmoptjs Costa. First antennae twice as long as the second; 
first 3 abdominal segments very large, last 3 small and bent beneath 
them: about 9 species. 

E. harts (S. I. Smith) (Fig. 585). Last 3 pairs of abdominal ap- 
pendages short and thick; length 10 mm.; color brownish; first gnathopods 
small, second large: Cape Cod to New Jersey, under rocks and among 
seaweeds near low-tide mark. 

Family 0. PHOTIDAE. 

First antennae with or without a small secondary flageltnm and longer 
than the second; mandible with a long palp; second gnathopods larger 
than the first: 10 genera and about 40 species. 

Lbptcoheixus Zaddach (Ptilocheirus Stimpson). Terminal pleopoda 
biramoee; both pajrs of gnathopods large and chelate; first antennae with 
a minute secondary flagellum : 8 species. 

L. pingins Stim. Body thick, and variegated in color; length 43 
mm. : New Jersey to Labrador; common on muddy bottoms, 

AMPB1P0DA 371 


First antennae with or without secondary flagellum and about the 
same length as the second; gnathopods large, the second being larger 
than the first; last pair of ab- 
dominal appendages end in 
hooks: about 6 genera and 30 

AxFmTHoU Leach. First 
antennae without secondary flaget- 
lum; head without rostrum; man- 
dible with palp: 17 species. n*. B8G— AmpMthot vauaa (pauimelBr). 

A. valida S. I. Smith (Pig. 
686). Antennae of about equal length and less than half as long as 
body: New Jersey and Long Island Sound under rocks and among 
i weed. 
A. longiman* Smith. First antennae as long as the body; gnathopods 
stout and elongate; length 9 mm.: 
common; Cape God to New Jersey, 
among eel-grass. 

Fault 8. COROPH1IDAE. 

Body depressed and abdomen 
small; first antennae with or without 
secondary flagellum; second antennae 
very large: about 11 genera and 45 
species; tube-dwelling. 
L CoROPHTtm Latreille. Mandibular palp two- 
jointed; no secondary flagellum; second antennae enor- 
mously developed in the male; gnathopods feeble: 12 

0. cylindricnm (Say) (Fig. 587). Length 5 mm.; 
color light, sometimes with spots: Maine to New 
Jersey, living free or in tubes in the mud or in 
sponges, etc. 

2. TJxioola Say. Body depressed; first antennae 
with secondary flagellum and a little longer than the 
second; telaon lamellar, rounded: 8 species. Fig. 683 

U. irrorata Say (Fig. 588). Color red, mottled (p»oimeier). 
with white; length 15 mm.; body broad; rostrum dis- 
tinct: Labrador to New Jersey; common on sandy or rocky bottoms, 
living in tubes, often not of its own construction. 




Body cylindrical; first antennae short, with secondary flagellum; 
second antennae longer than the first and with blade-like flagellum; 4 
abdominal segments; 3 pairs of caudal stylets present, the last pair 
being nearly as long as the rest of the body, but shorter in the female: 
1 genus. 

Ghslitaa Philippi. With the characters above given: 1 species. 

0. terebrans Phil. Length 6 mm.: New England coast, boring in 
submerged timbers, and often doing great damage; Europe. 

Suborder 3. CAPRELLIDEA. 

But 6 free thoracic segments; abdomen very rudimentary; body very 
elongate : 2 families and about 65 species. 


Body slender and cylindrical; first antennae longer than the second; 
gills confined to third and fourth free thoracic segments, on which 

the legs may be wanting: 2 genera, which live among 
seaweeds and on hydroids, holding on by the 3 pairs of 
long posterior thoracic legs, with about 50 species. 

1. Capbella Lamarck. Five pairs thoracic legs; 
mandible without a palp; gills and no legs on the second 
and third free thoracic segments; abdomen reduced to a 
small knob bearing a pair of rudimentary legs in the 
male: many species. 

0. geometric* Say (Fig. 589). Head with an ante- 
riorly projecting spine; antennae of nearly the same 
length; length 15 mm; color variable: Cape Cod to 
Virginia; very common. 

2. JEoikella Broeck. Like Caprella but with a palp 
on the mandible: several species. 

A. longicornis Kroyer (Fig. 590). 
First pair of antennae twice as long 
as the second; body either smooth or 
spiny; length 16 mm.; color variable: 
Labrador to New Jersey; Europe. 



Fig. 589 




Fig. 590 — JEginella longioomfo 

Order 2. ISOPODA.* 

Body usually flattened dorsoventrally and with gills on the abdomi- 
nal appendages; the anterior pairs of pleopods usually more or less 

• See "Synopsis of North American Isopoda," by Harriet Richardson, Am. Nat^ 
Vol. 34, pp. 207 and 295. "Monograph of the Isopods of North America," by same, 
Bull. U. 8. Natl. Mas., No. 54, 1905. 

I80P0DA 373 

lamellar and functioning as gills or longs, while the last pair, which 
are called uropods (Fig. 602) and have a distinct ezopodite and endopo- 
dite, are elongated and function as feelers or as swimming fins: about 
IS families and over 2,300 species, which are small, creeping or swim- 
ming animals, most of them marine, living under stones along the sea- 
shore and among seaweed or parasitic on fish ; a few live in fresh water, 
while several very familiar species are terrestrial. 
Key to the families of Isopoda here described : 

<H First pair of legs chelate .1. Tanaidae 

g, First pair of legs not chelate. 
&i Uropods lateral. 
Ot Uropods with telson forming a caudal fin ; pleopods mostly natatory. 

<*! Exopodite of uropod arches over base of telson 2. Anthubidae 

a\ Ezopodite of uropod does not thus arch. 
4 Abdomen composed of 6 segments. 
fx Both branches of uropod well developed. 
g x Not parasitic ; body more or less cylindrical ; eyes usually small. 


g t Parasitic on fish. 
Kx Body broad and flattened ; first 3 pairs of legs prehensile. .4. Motdae 

ft, Eyes large ; legs all prehensile 5. Ctmothoidae 

/ a The 2 branches of uropod not of same length, the ezopodite being 

minute ; animal bores in wood 6. Limnobiidae 

4 Abdomen composed of 2 segments 7. Spraebomidae 

e* Uropods arch over the other pleopods, covering them 8. Idotheidae 

&t Uropods terminal. 
o x Animals aquatic. 

a\ First antennae much smaller than the second, but not minute. 
4 Animals not parasitic. 

fx Fresh-water forms 9. Asellidae 

f % Marine forms 10. Jaxibidae 

e, Animals parasitic on decapods 15. Bopybidae 

d % First antennae minute and not easily seen 13. Lioydidae 

c, Animals terrestrial (occasionally aquatic). 
d\ Cannot roll itself into a ball (except Cylisticus convexut). 

^ End segment of abdomen pointed or angular 11. Onisoidae 

e, End segment truncate or indented ... 14. Tbichoniscidae 
d\ Can roll itself into a ball 12. Abmadhxididae 

Family 1. TANAIDAE. 

Body more or less cylindrical, with 6 free thoracic 
segments; first pair of legs chelate; abdominal append- 
ages, when present, natatory ; gills on the thoracic append- 
ages: about 16 American species; marine. 

1. Tanais Audouin and Edwards. Only 3 pair of 

pleopods present; uropods uniramose and short: 5 Amer- Tanais cavoiimi 

ican species. 

T. cavolini Milne-Edwards (Fig. 591). Body slender, abdomen with 

5 segments; uropods 3- jointed; length 4 mm.; width 1 mm.: Greenland 

to Long Island Sound ; in shallow water on piles and among seaweed. 



Fig. 592 




2. Leptochxla Dana. Male with large, female with small chelae; 
5 pairs of pleopods present; uropods biramose; eyes present: 5 American 

L. saYignyi (Kroyer) (Fig. 592). Chela of male elongated; ezopo- 
dite of uropods composed of 1, endopodite of 6 segments; 
length 2 mm; color white: New Jersey to Cape Cod; 
among seaweed and at the surface; Europe. 

Family 2. ANTHURIDAE. 

Body cylindrical and elongate, with 7 free thoracic 
segments; abdomen relatively short, with its anterior 
somites often fused together; uropods lateral, large, and 
expanded, the outer branch (ezopodite) arching over the 
telson: about 15 species, 9 American. 

Oyathtoa Norman and Stebbing. First 5 abdominal 
segments fused together so as to resemble an eighth 
thoracic; maxillipeds 3-jointed: 1 American species. 

0. carinata (Kroyer) (Fig. 593). Both pairs of 
antennae short and thick and with few hairs; length 18 
mm.; breadth 2 mm.; color brownish or yellowish: New 
Jersey to Greenland; on sand and mud bottoms in shallow 
water and among seaweed; Europe. 

Body 8emicylindrical and broad; abdomen composed Fig. 503 

* * ; r Cyathura 

of 6 segments ; uropods lateral, forming with the telson a carinata 

. . (Harger). 

caudal swimming fin: 23 American species. 

OntOUUTA Leach. First 3 pairs of legs prehensile, last 4 pairs 
ambulatory; first and second pair similar to each other: 
14 American species. 

0. concharnm (Stimpson) (Fig. 594). Length 23 mm.; 
breadth 8 mm.; telson triangular; base of uropods is 
extended posteriorly beneath the margin of the telson 
two-thirds of its length: South Carolina to Nova Scotia 
on muddy and sandy bottoms in shallow water, feeding 
on the blue crab and other animals. 

Fig. 504 




Family 4. ^OIDAE. 

Body broad and more or less flattened ; head short and 
broad, usually with 2 very large eyes on its upper surface; first 3 pairs 
of legs prehensile; uropods lateral and forming a caudal fin with the 
telson : parasitic on the skin of fish ; 30 American genera. 



JEftA Leach. Body elliptical in outline ; basal segments of first anten- 
nae expanded and lying entirely in front of the head : 14 American species. 

A. psora (L.). Salve bug (Fig. 595). Length 16 mm; breadth 10 
mm.: parasitic on the skate, cod, halibut, and other fishes; 
used as a salve by fishermen; Long Island Sound to 
Greenland; Gulf of Mexico; Europe. 


Head triangular, with large eyes, and extending over 
the base of the short antennae; all 7 pairs of legs pre- 
hensile, terminating in hooks: parasitic on fishes; over 
100 species, 27 American. 

Ltvoheoa Leach. Body elliptical, more or less 
asymmetrical; first pair of antennae widely separated at the base: 5 
American species. 

L. oralis (Say). Length 21 mm.; width 13 mm.: 
parasitic on the gills and in the mouth of the bluefish and 
occasionally of other fishes along the Atlantic coast south 
of Cape Cod, and in the Gulf of Mexico. 

Fig. 595 
JEaa ptoro 

Fig. 596 


Body flattened and with parallel sides; can roll itself 
into a ball; antennae short; eyes lateral; uropods lateral; 
legs ambulatory: 1 genus. 

LrJOTOBZA Leach. With characters of family : 1 species. 
L. lignorum (Rathke). Gribble (Fig. 596). Length 3 mm.; width 
1.5 mm.: Florida to Labrador; Europe; Pacific coast; makes burrows 
about 12 mm. deep in submerged timbers, causing 
great damage to docks, etc.; very common. 


Body short, oval, and convex, and in many species 
can be rolled into a ball; but 1 abdominal segment 
besides the large telson; inner branch of uropod 
immovable: 30 American species. 

Sfhjbboma Latreille. Uropods large, lateral, the 
2 branches being of equal length, the outer margin of 
the exopodite being denticulate; legs ambulatory: 3 
American species. 

8. qnadridentatum Say (Fig. 597). Body can be rolled into a ball; 
length 8 mm.; width 4 mm; color dark and variable: Florida to Cape 
Cod; under stones between tide lines. 

Fig. 597 





Family 6. IDOTHEIDAE. 
Body more or less broad and flattened; often elongate; abdominal seg- 
ments partially or completely fused; nropods lateral, arching over and cov- 
ering the other pleopods under the abdomen : about 90 species, 40 American. 
Key to the genera of Idotheidae here described : 

a, Side of head cleft and extending beyond eyes 2. Chimidoiia 

a. Side of bead not extended in dorsal view. 
6, Second antennae with a long nagellum; abdomen of several segments. 

1, inoTHu 
6, Second antennae without a long flagellum ; abdomen a single segment 

c, Second antennae not much longer than bead 3. Edote* 

c, Second antennae very much longer than head 4. Ebichsohella 

1. Idothka Fabric iiis. Second antennae with a long flagellum and much 
larger than the first; legs all alike; abdomen composed 
of 3 complete and 1 partial segment: 8 American species. 
I. baltica (Pallas) (Z. manna L.; I. irroraia Say) 
(Fig. 598). Length 20 mm.; width 7 mm.; color often 
green, but very variable; abdomen ending in three projec- 
tions: Nova Scotia to North Carolina; cosmopolitan; on 
seaweed, in sand or at the surface; common. 

L phosphores, Harger. Length 21 mm.; width 7 mm.; 
698 color variable; abdomen tapering to a point: coast of 

Idothea baitioa New England, among rocks and seaweed. 

I. metallic* Bosc (f. robuxta Kroyer). Length IS 
mm.; width S mm.; abdomen truncate: entire Atlantic coast; cosmo- 
politan; often on floating seaweed. 

Fig. 590 Fig. 600 Fig. 601 

Fig. 688— Chtridoteo coca (Harger). Fig. 600 — Baotea triloba (Harger), 

Fig. bOl— Ericktonella flltjarmit (Harger). 

2. Obwdotba Harger. Second antennae usually witb a short fla- 
gellum, sides of head cleft at the eye and extending beyond it; first 3 
pairs of legs prehensile, last 4 pairs ambulatory; abdomen composed of 
4 segments: 2 species. 

0. case* (Say) (Fig. 599). Body ovate, with a long, pointed telson; 
length 8 mm. ; width 4 mm. ; antennae of nearly equal length ; eyes small, 
dorsally placed: Florida to Nova Scotia; at the surface or in the sand. 


3. Edotea Guerin. Second antennae of 4 to 6 segments and short ; 
abdomen composed of a single segment; legs prehensile: 3 species. 

E. triloba (Say) (Fig. 600). Length 7 mm.; width 3 mm.: New 
Jersey to Maine; under stones and decaying algae, in muddy places 
along the shore. 

4. EBXOHBonLLA Benedict. First antennae short; second antennae 
long and composed of 6 segments; abdomen composed of a single seg- 
ment; legs ambulatory: 3 American species. 

E. flliformis (Say) (Fig. 601). Length 8 mm.; width 3 mm.: At- 
lantic coast, south to Cape Cod ; in sand and among algae in shallow water. 

Family 9. ASELLIDAE. 

Body flattened, with 7 free thoracic segments, and with the ab- 
dominal segments forming a single, shield-like plate; abdominal append- 
ages exclusively branchial and numbering 4 or 5 pairs ; uropods terminal 
and biramose: principally fresh-water animals; 17 American species. 

Key to the genera of Asellidae here described: 

0| Eyes present 

6j Last 6 pairs of legs uniunguiculate ...1. Asellus 

o» Last 6 pain of legs biunguiculate. 2. Mancasellus 

a. Byes absent ; cave-dwellers .3. CiBCiDOTEA 

1. ASSLLTTB Geoff roy. Abdomen about as broad as long; legs uniun- 
guiculate; mandible with a palp: 7 American species; in fresh water. 

A. communis Say (Fig. 602). Length 15 mm.; breadth 5 mm.; first 
antennae short, second long; first pair of legs prehensile and subchelate, 
the others ambulatory, the last 3 being longer than the others: eastern 

United States; the commonest __ 

fresh-water isopod, occurring ^teflBBBHBH^S^Wi 
generally among vegetation. /y S^jJ SPflT 

2. Manoasellus Harger. c 
Abdomen about as broad as 
long; mandible without a palp; V FI * *°?— •? 1 *» ran ! of Aniiuttnmmunu, 

8 ' ***«**"** fcW wi» U vu» «, po»F» showing the internal organs (McMurrich). 

last 6 pairs of lees biun- h ? ecoI » d antenna ; 2, first antenna; 3, 
*«»»» v F «i«o vi *^ e o i/*«« brain; 4, stomach; 5, mandible; 6, maxll- 

guiculate: 6 species; in fresh $ n < e d . ; 10 '' o£™ d fii?gi& lle * rt; °' lnteB " 

M. macrourus Garman. Length 12 mm.; breadth 5 mm.; first pair 
of legs subchelate, the others ambulatory ; side of the head cleft near the 
eye: central United States east of the Mississippi, often in caves. 

3. Cjeoidotea Packard. Body elongate and narrow; eyes wanting; 
abdomen much longer than broad: 4 species; in caves and similar places. 

0. stygia Pack. Length 10 mm.; width 2 mm.; first pair of legs 
prehensile, the hand being armed with 2 long and 3 short teeth: central 
United States; in caves and deep wells. 


Family 10. JANIBIDAE. 

Body flattened and similar to the Asellidae, with the side of the head 
usually expanded under the eye; first pair of abdominal appendages in 

the female form a single large opercular plate, and 
^"■^ i^"*^\ "* ^ e mBL ^ e together with the second pair form 
f *i jwfcj^ \ * compound operculum: 20 American species; 
^. r? — ^a f marine. 

1. Jxra. Leach. First pair of antennae very 
small; uropods very small: 2 American species. 
J. marina (Fabricius) (Fig. 003). Body 
oval, 5 mm. long, 2 mm. wide, and very variable 
in color, usually being mottled gray; legs ambu- 
latory and triunguiculate : coast of New England; 
Fig. eo fcjJ2JX marina Europe ; common between tide lines under stones 

and seaweeds. 
2. Janzba Leach. First pair of antennae and uropods well devel- 
oped; side of head not expanded, or but slightly so: 5 American species. 

J. alta (Stimpson) (Fig. 604). Length 7 mm.; 
width 2 mm.; legs biunguiculate : Atlantic coast from 
Nova Scotia to Virginia, from low-water mark to 500 

Family 11. ONISCIDAE. 

The sow bugs. Terrestrial isopods with an 
elliptical body, which is more or less flattened and 
cannot be rolled into a ball (except Cylisticus con- 
vexu8) ; first antennae minute; second antennae long; Fir. 604 — Janira 
thorax with 7 and abdomen with 6 free segments; 
legs ambulatory; 5 pairs of pleopods are respiratory plates, the second 
pair in the male terminating in a pair of long slender stylets; uropods 
long and terminal: common under logs, etc., and in other dark, damp 
places on the land; 200 species, 30 American. 

Key to the genera of Oniscidae here described : 

a, Antennae ending with 3 short segments forming the flagellum. 

b x Abdomen not abruptly narrower than thorax 1. Oniscus 

6, Abdomen abruptly narrower than thorax 2. Phxlosoia 

o, Antennae ending with a flagellum of 2 short segments. 
&i Abdomen not abruptly narrower than thorax. 

Cj Body convex, can be rolled into a ball 3. Cylisticus 

6» Body flattened, cannot be rolled into a ball 4. Pobckllio 

b, Abdomen abruptly narrower than the thorax 5. Mbtoponobthus 

1. Ovxsous L. Body broad, flattened, with a granulated or tuber- 
eulated surface; antennae ending with 3 short segments; side of head 
extended beneath the eyes: 1 species. 



0. Melius L. (Fig. 605). Length 16 mm.; width 8 mm.; color deep 
slate, spotted with white, and white along the lateral edges: eastern and 
central states; Europe; common under bark of fallen 
trees, logs, stones, etc. 

2. Philobcta Latreille. Second antennae ends 
with 3 short segments; side of head not extended 
under the eyes; abdomen abruptly narrower than the 
thorax: 7 American species. 

P.TitUtaSay (Pig. 606). Length 8 mm. ; width 
4 nun.; color usually dark brown with 2 darker 
median stripes: along the seashore from New Jersey 
to Cape Cod, under stones and boards above high tide. 

3. Otlibtiotib SchnitEler. Body rather elongate, 

Flf. 60B — Onitout 

smooth, very convex, and able to be rolled into a <u«fln* (Paolmcier). 

ball; head with lateral lobes; second antennae long, 

ending with 2 short segments; uropoda long: 1 Amer- 
ican species. 

C. convoxus (DeOeer) (Fig. 607). Length 12 mm.; 
width 5 nun. ; color brown or dark gray, spotted with 
white: eastern and central states; Europe; under logs 
and stones in rather dry places. 

4. Poboellio Latreille. Body oval, flattened; head 
with lateral lobes; second antennae long, ending with 2 
short segments; uropods long; respiratory plates of 
either the first 2 or all 5 pairs of pleopods provided 
with tracheae: 6 American species. 
P. rathkei Brandt. Body granulate, 10 mm. long and 5 mm. wide, 

yellowish-brown in color with numerous black blotches and two lateral 

and usually a median light stripe: eastern and central states; Europe; 
common under boards, stones, etc. 


P. sober Lat. (Fig. 60S). Body covered with minute tubercles, 12 
mm. long, 7 mm. wide, of uniform black color, without spots or blotches: 
entire America; cosmopolitan; under bark, logs, etc. 

P. lawlB Lat. Body smooth or minutely granulate, 15 mm. long, 8 
mm. wide, dark gray in color with 2 wavy median lighter bands: entire 
America; cosmopolitan. 

5. Metofokoethca Budde-Lund. Body oval, flattened, without lat- 
eral lobes; second antennae long, ending in 2 short segments; abdomen 
abruptly narrower than thorax; uropods long: 4 American species. 

H. prainomw (Brandt) (Fig. 609). Length 9 mm.; width 4 mm.; 
color reddish-brown in the hinder and lateral portions, and lighter in 
the other portions: entire America; cosmopolitan; under logs, etc. 

Body convex and able to be rolled into a ball; first antennae minute; 
second antennae short; uropods short and not extending beyond the 
terminal segment: terrestrial; 6 genera 
and 23 American species. 

Abxadiixidiuh Brandt. Pill bugs. 
With the characters of the family; exopo- 
dite of uropod large and lamellar; ter- 
minal segment triangular: 2 species.' 

A. vulgar* (Latreille) (Fig. 610). 
Length 16 mm.; width 8 mm.; color black 
or dark gray with rows of indistinct spots: entire America; cosmo- 
politan: under stones, etc., in damp places. 

Family 13. LIGYDIDAE. 

Body elliptical or elongate; first antennae minute; second antennae 
long, with numerous small terminal segments; buccal 
mass prominent; uropods long: marine; 2 genera and 
12 American species. 

Liqyda Raflnesque. The two branches of the 
uropods of about equal length and styliform: 6 
American species. 

L. exotica (Rous) (Fig. 611). Body elongate, 48 
mm. long (with uropods), 14 mm. wide: Florida to 
North Carolina; California; cosmopolitan; among 
rocks and on piles and docks; common. 

L. ooaanlca (L.). Body oval, 22 nun. long (with uropods), 
wide, and with a granulate surface : New England ; Europe. 


Body elliptical, elongate; first antennae minute; second antennae end- 
ing with 3 or 5 small segments ; abdomen not pointed behind, but truncate 
or indented; the 2 branches of each uropod of about the same length: 4 
American species; terrestrial or in fresh water. 

TfiiOHOBiBOUB Brandt. Head rounded in front; eyes small, composed 
each of 3 ocelli; second antennae long; abdomen abruptly narrower than 
thorax: 2 species. 

T. pnsUlns Br. (Fig. 612). Length 3 mm.-, width 1 
mm.; body smooth: entire North America; Europe; 
under moss, in the woods. 

Parasites of decapods; male and female animals 
dissimilar, the female being asymmetrical and broad, and 
sometimes much deformed, the male more slender and 
symmetrical; antennae rudimentary; legs prehensile: 35 
species, 29 American. 

1. PaoBOPTKUS Giard and Bonnier. Segments of THcHmlmm* 
abdomen distinct in female, but fused, except at the (EicS«ralion) 
edges, in the male; 5 pairs of abdominal appendages; 

nropods wanting: parasites in the gill chamber of decapods; 5 American 

P. pantUUcola (Packard). Body (of female) 5 mm. long, white in 
color with black markings; the female lies against the body of the host, 
the ventral side of the thorax having the brood poach with the eggs, 
the much smaller male is usually found clinging to the female: entire 
Atlantic coast, on Palamonetes, producing large tumors under the 

2. Phxtxvs Rathke. Body of female very asymmetrical, one side 
being greatly swollen ; 5 abdominal segments ; the legs of the longer side 
of the body wanting, except on the first thoracic segment, on the shorter 
side very small; antennae and uropods rudimentary; abdomen of male 
composed of a single triangular segment, without appendages: parasitic 
on the abdomen of decapods; 1 species. 

P. ahdomlnaliB (Kroyer). Body of female 9 mm. long, 7 mm. wide; 
of male 3 mm. long and 1 mm. wide: circumpolar, extending to Vineyard 
and Puget Sounds; on the abdomen of Pandalus and other prawns. 

3. Boftxoxdsb Stimpson. Body of female somewhat asymmetrical, 
with 6 abdominal segments and 7 pairs of legs, without abdominal ap- 
pendages; abdomen of male forming a single piece without appendages; 
antennae rudimentary: 1 species. 


B. hippolytes Kroyer. Body of female 8 mm. long and 7 mm. wide; 
of male 3 mm. long and 1 mm. wide: circumpolar, extending to Boston 
and to Puget Sound; on the gills of Pandalvs and other prawns. 

Division 3. THOBAOOSTRAOA.* 

Malacostraca often of large size in which 3 or more of the thoracic 
somites are fused with the head, and the cephalothoraz thus formed is 
covered with a carapace; projecting forwards from the anterior end of 
the carapace in most species is the spike-like rostrum; eyes at the end of 
movable stalks or peduncles (except in the Cumacea) ; the sixth pair of 
pleopods (uropods) together with the last body segment (telson) forms, 
except in the case of the crabs, a swimming fin, by striking which vigor- 
ously beneath the body the animal propels itself rapidly backwards; 
the eggs and sometimes the young usually carried beneath the abdomen 
attached to the pleopods, the young in most forms passing through a 
metamorphosis before attaining the form of the parents: 4 orders. 

Key to the orders of Thoracostraca: 

Hi Carapace does not cover the entire thorax. 

t>x Thoracic appendages all biramose 1. Schizofoda 

o, Thoracic appendages not all biramose. 
Ot Abdomen large and wider than the small cephalothoraz. . .2. Stomatopoda 

o, Abdomen narrow 3. Cumacea 

o, Carapace covers the entire thorax 4. Decapoda 


Body elongate and usually more or less transparent and with a thin 
carapace which covers nearly all of the thorax; the 8 thoracic feet may 
all support gills and are biramose, the anterior 2 pairs being slightly 
modified to form maxillipeds; eggs carried beneath the thorax as in the 
Arthro8traca; young born in some species as nauplii: 3 families and 
about 300 species, mostly marine; 11 American species. 

Family MYSIDAE. 

No gills present; first 2 pairs of thoracic appendages (maxillipeds) 
shorter than the following 6; abdominal appendages often rudimentary 
in female; the endopodites of the uropods bear each an auditory sac; 
2 to 7 pairs of marsupial plates beneath the thorax within which the 
young develop: 21 genera and 90 species, mostly marine. 

1. Mtsis Latreille. Body laterally compressed; fourth pair of ab- 
dominal appendages in male are long stilets; antennal scale long: often 
in swarms in the North Atlantic; 23 species, 4 American, 1 in fresh 

• Bee "The Stalk-eyed Crustaceans of the Atlantic Coast,*' etc, by 8. I. Smith, 
Trass. Conn. Acad., Vol. 5, p. 27. 


M. stenolepis B. I. Smith (Fig. 613). Body cylindrical; carapace 
with a short, bloat rostrum, and with its lower anterior margin extended 
to form a sharp tooth ; body bends between the first and second abdom- 
inal segments ; length, mala, 
23 mm., female, 30 mm.; 
color white, with bock stel- 
late spots: coast of New 
England and southwards, 
often common in eel grass. 

Fig. 613— llytii limohpt* (Paauneler). 

.... ..- _. DeoU. 

„ first antenna ; 2, scale of second 
3, second antenna. 

Fl». 614 — M*** rtUeta 

1, fUgella -* "-■* ""' 

\ Loven (Fig. 614). Body slender, 18 mm. long: 
in Lakes Superior and Michigan; Europe and 
Asia, in largo fresh-water lakes. 

2. HxraonTBn S. I. Smith. First pair of thoracic 
legs larger than the others 
and ending each with a 
claw; antennal scale very 
small; abdominal append- 
ages rudimentary in both 
male and female: one 

H. formosa Smith. Length of male 6 mm., of female 8.5 mm; 
females rose-colored; males colorless: coast of New 
England, in eel grass or often in dead mollusk shells, 
sometimes in swarms. 


Body large, with a small fiat carapace which does 
not cover the posterior thoracic somites, with a broad 
elongated abdomen bearing gills on the appendages; 5 
pairs of maxillipeds, the second pair being much larger 
than the rest and snbchelate, and 3 pairs of periopode; 
heart long and tubular; liver, testes, and ovaries extend- 
ing the length of the thorax and abdomen, the testes 
being a pair of delicate tubes and the ovaries a broad 
median band: 10 genera and about 00 species, all 
marine; often used for food, 

Sodtlla Fabricius. Five posterior thoracic 
somites not covered by the carapace, of which the first 
is very small and the second has a lateral spur on each side and the but 
3 bear the periopods: 21 species. 

Fig-. 61 — BguiOa 
tmpu.a ( 

tenna ; 2, second 

of second antenna ; 
4, second ma x 1111- 

r; S, perlopodi ; 


S. empusa Say (Fig. 615). First antennae with 3 flagella; second 
shorter and with a very large flat scale (exopodite); length up to 25 
cm.; color greenish-gray: Florida to Cape Cod, in shallow burrows in 
the mud, between tide lines and in shallow water, each burrow usually 
having 2 or 3 openings a few feet apart; often very common. 

Order 3. OUMAOEA. 

Body small, with a small carapace which does not cover the hinder 
4 or 5 thoracic somites, and with a long slender abdomen; first anten- 
nae short; second antennae short in the female and long in the male; 
mandibles without palp; 2 pairs of maxillipeds and 6 pairs of periopods 
present, 2 to 5 pairs of the latter being biramose (small exopodite pres- 
ent) ; the pleopods, with the exception of the uropods, wanting in the 
female, while in the male 2 to 5 pleopods may be present; a single pair 
of gills on the first pair of maxillipeds; eyes close together and sessile or 
wanting ; the large eggs are carried by the female in a brood pouch under 
the foremost free thoracic segments and the hinder part of the cara- 
pace; the young animals are like the parents in appearance, but are 
without the last pair of thoracic and all the abdominal legs when born: 
9 families and about 300 species, all marine and living mostly in the sand 

and mud. 


With the characters given above: 8 American genera. 

Dzasttlxb Say. Seven abdominal segments present, the telson 
being well developed and long and pointed; a single eye or none; the 
3 anterior pairs of periopods in the female 
and the 5 in the male biramose: numerous 
species, several American. 

D. quadrispinosa G. 0. Sars (Fig. 
616). Length 10 mm.; body flesh color or "* 016-^tj^adre.p^o 

brownish; a short spine projects from the 

carapace on each side a little behind the large triangular rostrum: Nova 

Scotia to New Jersey in 2 to 200 fathoms; often very common. 

Order 4. DEOAPODA. 

Shrimps, crayfish, lobsters, and crabs. Thoracostracans in which 
the carapace covers the entire thorax, the cephalothorax being cylindrical 
in the Macrura and broad and more or less flattened in the Brachyuro; 
gills on the thorax, extending either from the legs (podobranchs), the 
joints (arthrobranchs), or the body wall (pleurobranchs) and situated 
in the gill chamber on each side of the body (Fig. 623) ; abdomen well 


developed in the former group and small and bent under the cephalo- 

thorax in the latter; 3 pairs of maxillipeds and 5 pairs of periopods 

present; first pair of periopods (chelipeds) usually much larger than the 

others and chelate, forming the pinching claws (chelae) ; other periopods 

also often chelate ; eggs and sometimes the young carried on the pleopods : 

about 6,000 species, mostly marine; the crayfish, certain crabs, and a few 

others being fresh- water or terrestrial animals; 2 suborders. 

Key to the suborders of Decapoda : 

Ox Body more or less cylindrical and elongate; antennae long; tail fin 

usually present 1. Macbura 

a t Cephalothorax short and broad, with the abdomen bent under it ; crabs. 

2. Bbaohytjba 

Suborder L MACRURA.* 

Body more or less cylindrical and elongate with a well-developed 
abdomen, at the hinder end of which is usually a swimming fin formed 
of the sixth pair of pleopods (uropods) and the telson; antennae well 
developed and usually long, the first antenna having 2 or more flagella, 
the second usually with an antennal scale; the young are born as nauplii 
in Peneus and Lucifer, but in most other forms in a more advanced larval 
stage: about 10 American families grouped in 4 tribes. 

Key to the tribes of Macrura: 

Ox Last pair of thoracic feet normal ; swimming fin present 
&i Shrimps and prawns; body rather small and transparent; antennal 

scale large (Fig. 617) 1. Cabidea 

b % Burrowing marine animals of moderate size; antennal scale usually 

absent 2. Thalassinidea 

6, Crayfish and lobsters ; body of moderate or large size, with small anten- 
nal scale, or none 3. Astacidea 

<h Last pair of thoracic feet reduced and projecting upwards ; no swimming 

fin ; hermit crabs, etc 4. Anomuba 

Tbibjc 1. GARH)EA.t (Macbura natantia.) 

Shrimps and prawns. Small forms with a compressed and more or 
less transparent body; carapace smooth, without sutures and with a long 
rostrum; antennal scale large; thoracic legs usually long and delicate: 
about 17 families and several hundred species. 

Key to the families of Caridea here described : 

Ox First 3 pairs of periopods not all chelate. 
6, Second pair of periopods only chelate; first pair very stout and sub- 

chelate 1. Cbangonidae 

ft, First 2 pairs of periopods usually chelate ; first antennae with 3 flagella. 

2. Pauemonidab 
a, First 3 pairs of periopods chelate -» . . .3. Peneidak 

• See "Embryology and Metamorphosis of the Macroura," by W. K. Brooks and 
F. H. Herrick, Mem. Nat. Acad. Sci., Vol. 5, 1802. 

t See "Synopsis of the Caridea of North America," by J. S. Klngsley, Am. Nat* 
Vol. 33, p. 709, 1890. 



Shrimps. Second antennae long, with a large antennal scale; first pair 
of periopods much stouter than the others and subchelate; second pair of 
periopods small and chelate; mandibles slender, not bifid or expanded at 
the tip and without a palp: marine; about 10 American genera. 

Obavgon Fabricius. Cephalothorax 
somewhat depressed; rostrum short; first 
antennae with 2 flagellar 15 species, about 8 

0. vulgaris Fabr. The edible shrimp 
(Fig. 617). Length 5 cm.; color light, with 
dark markings: Labrador to South Caro- 
lina; Europe; Pacific coast; common at the 
bottom of sandy bays, in shallow water, often 
buried in the sand. 
(iI?ni8® 17 ^f r fl"fraSte^ 0. boreas (Phipps). Three median dor- 

scale;* ^serond'anieniia? 01 * 8al spines on cephalothorax : Atlantic coast as 

far south as Cape Cod; North Pacific coast. 

0. francigcornm Stimpson. The California shrimp. Length 7 cm.; 
posterior margin of fifth abdominal segment with a spine on each side; 
movable finger of cheliped long and parallel with the hand: common at 
San Francisco. 


Prawns and shrimps. Second antennae long, with a large antennal 
scale; first antennae with 3 flagella; third maxillipeds foot-like; mandibles 
with a bifid tip; rostrum long and usually serrate: mostly marine; about 
12 American genera. 

Key to the genera of PdkBtnonidae here described : 

Oi Right and left claws of the first pair of periopods of the same sise. 
bx First pair of periopods shorter but not thicker than the second. 
Cj First 2 pairs of periopods chelate. 

dt Mandibular palp absent 1. Paljbmonetbb 

d, Mandibular palp present 2. Paxjsmon 

c, First pair of periopods not chelate 3. Pandalus 

6, First pair of periopods thicker than the second ; abdomen bent down at 
the third segment 

c x Mandibular palp present 4. Hiffolttb 

c, Mandibular palp absent 5. Vibbxus 

a, Bight and left claws of the first pair of periopods of different size. .6. Alpheus 

1. Paxjbmonetes Heller. Mandibles without palp; first 2 pairs of 
periopods chelate, the first pair being smaller than the second: about 6 
species, 3 American, in salt, brackish, and fresh water. 



P. vulgaris (Say). Common prawn (Fig. 618). Rostrum long, 
straight and serrate; length 45 mm.; body translucent, with brownish 
spots: Massachusetts to Florida; common on rock weed, and eel grass 
on muddy bottoms, often where the water is brackish or fresh. 

P. paludoaft (Gibbee). 
Length 35 mm.; rostrum serrate 
below as well as above : in 
fresh-water lakes and streams 
in eastern North America (Lake 
Erie, etc.). 

2. Paumon 

Fa ncius. la e ^ ^ fi^ MB— Palawoaatit eafcarfi (Ttriin). 

Palsemonetes but / 

with a 3-jointed mandibntary palp (Fig. 619): about 70 species, 3 
American; in salt and fresh water. 

P. obionis S. I. Smith. Length 6 cm.; carapace about a quarter the 
length of the body, with a lateral spine on each side: Ohio and Missis- 
sippi Rivers; often used for food. 

3. Pamdaltts Leach. Deep-water prawns. First 
and second pairs of periopods slender, the first 
not chelate, the second chelate : 10 American 

P. montagni Leach. Length 10 cm.; body with 

transverse red stripes; appendages thickly spotted 

with red: Chesapeake Bay to Greenland; Europe; in 

10 to 100 fathoms. 

1. HlFFOLTTS Leach. First 2 pairs of periopods chelate, the first 

pair shorter and thicker than the second; abdomen sharply bent down 

at third segment; mandibular palp present: numerous species, about 

30 American. 

H, pnsiola KrByer. Length 25 mm. ; 
pale gray or flesh color, brightly spotted 
with red, usually with a mid-dorsal 
white stripe, and sometimes 
with transverse bands of red 
and white: often common on 
rocky bottoms in shallow water from Vineyard Sound to Greenland; 

5. Vranros Stimpson. Similar to ffippolyte bnt without a man- 
dibular palp: many species, 2 American. 

V. Eostaricola S. I. Smith (Fig. 620). Rostrum straight and as 
long as the carapace, the latter being smooth and with 3 spines on an- 


terior part; abdomen sharply bent at the third segment; length 15 to 26 
mm. ; color translucent, usually greenish and spotted with red : Vineyard 
Sound and southwards, common in eel grass. 

6. Alpheus Fabriciufi. First pair of periopods larger than the 
others and chelate, the right and left claws of the first pair being thick 

and of very unequal size; rostrum small 
or absent; abdomen not sharply bent; 
eye stalks short and hidden: about 
one hundred species, twelve American, 
living principally along our southern 

A. minus Say. Rostrum present; 
hinder feet with spines beneath; length 
Pig. Q2i—M£heu8jeterocheU8 4 cm . : Atlantic coast from New Jersey 

to Florida; southern Calif ornian coast. 
A. heterochelis Say (Fig. 621). Large claw with a constriction at 
its middle; rostrum spiniform; length 5 cm.: Virginia to Florida; 

Family 3. PENEIDAE. 

Southern shrimps and prawns. First 3 pairs of periopods chelate, 
the third pair being the largest; rostrum long; second antennae long, with 
a large scale; abdomen compressed and not bent sharply: about 2 
American genera, marine, inhabiting chiefly the tropics and the deep sea. 

Peneub Latreille. Rostrum serrate; eye stalks jointed; the young 
born as nauplii: 3 American species. 

P. setiferus (L.). A lateral groove on each side of the forward half 
of the carapace; flagella of first antennae very short; length up to 16 cm.: 
common in shallow water along the coast from Virginia southwards, 
where it is an article of food, the larger individuals being known in the 
market as prawns and the smaller as shrimps. 

P. brasiliensis Latreille. Like P. setiferus, but with the lateral 
grooves extending the length of the carapace: Atlantic coast north 
to Cape Cod, occurring with P. setiferus. 


Animals of moderate size, with a cylindrical or flattened and trans- 
lucent body and a large abdomen; carapace with 2 longitudinal sutures; 
antennal scale usually wanting; first pair of periopods form pinching 
claws of unequal size: marine, burrowing animals; 3 families and about 
75 species. 

♦ See "Synopsis of Astacold and Tbalasslnold Crustacea/* by J. S. Kingsley, Am. 
Nat, Vol. 83, p. 819, 1899. 


With the characters given above: about 7 American genera. 

1. Callzavaha Leach. Cuticula soft and smooth; first 2 pairs of 
periopods chelate, the first pair being large and very unequal in size; eve 
stalks flattened ; third pair of maxillipeds flattened : about 20 species, 6 

C. Btimpsonl S. I. Smith. Length 6 cm.; 
small cheliped about half as long as the large 
one; carapace smooth and glossy: from Long 
Island Sound southwards, in burrows in the 
mnd between tide lines and in shallow water. 

2. Gebia Leach. Cuticula soft and smooth; Fig. 622— oetna ojjiiii* 
forward portion of cephalothorax compressed, 

with a triangular, hairy rostrum; second pair of periopods not chelate; 
third pair of maxillipeds pediform: 10 species, 2 American. 

Q. afflnis Say (Fig. 622). Length 10 cm.: Long Island Sound to 
South Carolina, living in burrows in the mud between tide lines and in 
shallow water. 

Tares 3. ASTACLDEA. 

Lobsters and crayfish (Sig. 623). Body of moderate or large size 
and with a thick shell; first antennae with 2 fiagella, second either with a 
scale or with none and much longer than the first; no longitudinal 
sutures, but usually a transverse cervical suture in the carapace: 4 
families and about 150 species. 

Key to the families of Aatacidea here described : 
o. Antenna] scale nod cheliped present 

6, Animals marine 1. Nephbopsidax 

b, Animals in freshwater 2. Astactdae 

o, Antenna! scale and cheliped absent 3. P.UJNUaiDAE 


Lobsters. Body of large size; rostrum dentate along the lateral 
margins; first 3 pairs of periopods chelate, the first pair very large, 
forming the pinching claws: 3 genera. 

Hoxarub Milne-Edwards. Rostrum with 3 teeth on each side ; sec- 
ond antennae with a small scale; eyes round: 2 species. 

H. amerlcanns* M.-Ed. American lobster. Length up to 60 cm.; 
greatest weight 13 kg. or over 28 pounds; length of the average adult 
lobster 25 cm.; average weight less than a kg. or about one and three- 
quarters or two pounds; color usually dark green with darker spots and 

• Bee "The American Loblter," etc., bj F. H. Herrlck. Boll. TJ. S. Fish. Com. for 
1896. "Natural History of the American Lobster," by same, Ball. Bureau Fish., Vol. 
29, p. 149. 1809. 



yellowish underneath: Atlantic coast from Labrador to North Carolina, 
in shallow water in summer and in deeper water in winter. Lobsters are 
caught mostly off the coast of Canada and the New England states and 
are our most important 
food crustacean. The an- 
nual catch has amounted 
to over 100,000,000 in 
some years but is now 
much less. 

Family 2. ASTACIDAE.- 
Crayfish. Body not so 
large as in previous fam- 
ily; rostrum without lat- 
eral teeth: several genera 
and over 100 species; in 
fresh water. 

Key to the genera of 
Aataddae here described: 
a. Pacific slope crayfish. 

a, Atlantic slope and 
Mississippi valley 
crayfish. 2. Camsabuh 

Fig. 823 — A diagram or ■ crayflah abowln 
ar range me n t of internal organs (McMurrleb) ; I 
diagram of croan section of toe cepbnlotbora 
showing gill chamber ; C, Interior of gill chambe 

, pleura 

living t 

last thoracic roo 

tt, flrit periopod 
liver : 13. heart 

14, gonad ; 

e chord;' 20, kidney.' 

■od; 8, gills; 
atomach; 12, 

1. Astaods Fabricius. 
A pair of gills (pleuro- 
branehs) on the last tho- 
raeic somite (Pig. 623, 
C, 6), and 18 pairs in all: about 15 species, 5 on the Pacific slope, the 
remainder in Europe and Asia. 

A. nigresceiu Stimpson. Chelae naked on outer face; margins of 
rostrum denticulate; length 10 cm.; color dark greenish: San Francisco 
to Alaska, near the coast; used for food. 

2. CAMBABUsf Erichson. Common American crayfish (Fig. 623). 

* See "Monograph of the North Americas Astaddae," by H. A. Hagen, Hem. Maa. 
Comp. ZooL, V«l. 3, 1870. "The Crayfish," by T. II. Hnxley, 1881. "A Revision of 
the Aataddae," by W. Faxon, Mem. Mua. Comp. Zoo)., Vol. 10, 1S8G. "Ob serrations 
on the Aataddae," etc., by W. Faxon, Proc. U. 8. Nat. Mua.. Vol. 20, p. 043, 1898. 
"Synopsis of the Aataddae of North America," by W. P. Hay, Am. Nat, Vol. 33, p. 
997, 1809. "The Young of the Crayflah Aatacua and Cambarus, " by E. A. Andrews, 
Smithsonian Contributions to Knowledge, Vol. 30, p. 1, 1907. 

t See "Ecological Catalogue of the CrayQahes Belonging to the Genua Cambarus," 
by J. Arthur Harris, Kansas Univ. Sd. Bull., Vol. 2, p. 61, 1903. "Tbe Crawfishes 
Of tbe State of Pennsylvania," by A. B. Ortmann, Memoirs of tbe Carnegie Museum, 
Vol. 2, p. 343, 1906. "Breeding Uabita of tbe Crayfish," by E. A. Andrews, Am. Nat., 
Vol. 38, p. 16S, 1904. 



6 c" J> 

■The anterior abdominal appendage 

Pig. 62 
(male) in CamJ>arus (Ortmann). A, O. pro- 
pinquu»; B, (7. limosus; C, C. bartoni; D, 
O. aiogenes. 

No gills on the last thoracic somite and 17 pairs in all; first pair of 
swimmerets bifid and often hooked at the apex in the male: about 70 
species, all in North America 
and east of the Rocky Moun- 
tains. The animals live in 
streams, lakes, and swamps, 
resting under stones or in 
burrows or among aquatic 
vegetation near the surface; 
a few species are terrestrial, 
living in burrows. Crayfishes 
are omnivorous feeders, eat- 
ing decaying animal and plant substances, but also living animals and 
plants. Spawning occurs in the springtime and pairing in the fall in the 

case of C. diogenes and C. limosus 
and others, but C. bartoni and others 
probably pair and spawn the year 
round. The eggs are carried by the 
mother attached to her abdominal 
legs until they hatch; the young ani- 
mals when born have the form of the 
parents and live for a while with the 
mother, holding on to her abdominal 
legs with their claws. Crayfishes are 
used for food in New York and other 
large cities. 

0. bartoni* (Fabricius) (Fig. 624, 
C). First pair of abdominal append- 
ages of the male terminated with 2 
strongly recurved tips; length 8 cm.; 
the eastern specimens have a short 
quadrangular rostrum ; in the western 
specimens the rostrum tends to be 
elongate; body with few or no hairs; 
carapace depressed: North America, 
almost to the Mississippi, but espe- 
cially along the Atlantic slope, usu- 
ally in clear, small streams, but also 
occasionally in muddy ones where it may burrow; one of our most 
widely distributed and commonest crayfish. 


Fig. 625 — Oambarus pellucidus 
(Kingsley). 1, first antenna; 2, 
second antenna ; 3, antennal scale ; 
4, periopods; 5, carapace; 6, abdo- 
men ; 7, uropod ; 8, telson ; 9, rostrum. 

• See "Notes on the Habits of Certain Crayfish," by C. C. Abbott, Am. Nat., Vol. 
7, p. 80, 1878. 


0. limosus (Rafinesque) (C. affinis Say) (Fig. 624, B). First pair of 
abdominal appendages of the male terminated with 2 short, straight, diver- 
gent tips; length 10 cm.; body hairy all over; sides of carapace spiny; 
rostrum broad with parallel sides: eastern North America, not west 
of the Alleghenies; common in the larger rivers, usually does not 
burrow; the crayfish which is most commonly sent to the New York 

0. pellucidufl (Tellkampf) (Fig. 625). First pair of abdominal 
appendages clavate, the outer part being truncate and toothed; eyes 
atrophied; length 9 cm.: in caves in Indiana and Kentucky. 

0. diogenes Girard (Fig. 624, D). First pair of abdominal appen- 
dages in male terminate with 2 strongly recurved tips; rostrum rather 
slender; length 8 cm.: widely distributed and often common in the entire 
country east of the Rocky Mountains; preeminently a burrowing species, 
being found in swamps and meadows often far from a stream; the bur- 
rows are from 1 to 3 feet deep, with an enlargement at the bottom filled 
with water; often with a chimney to the height of several inches over 
the top. 

0. virilis Hagen. First pair of abdominal appendages in male acute, 
tapering, divergent; length 8 cm.: common in central states, in large 
rivers and lakes. 

0. propinquus Girard (Fig. 624, A). First pair of abdominal appen- 
dages in male terminating in 2 elongate straight convergent tips ; length 
7 cm. ; rostrum with a median ridge : common throughout the central part 
of the country, especially in large rivers and lakes. 



Spiny lobsters. Body of large size; antennal scale absent; none of 
' the periopods chelate: several genera. 

PAVxrLntxrs Gray. Rostrum absent ; flageUa of antennae long: several 


' P. argus (Latreille). Florida crayfish. First pair of antennae with 

I a very long basal joint; body 20 to 40 cm. long; color violet, red, and 

brown: common on coral reefs off the Florida coast; an important article 

of food. 

Trim 4. ANOMU&A. 

; Last pair of thoracic legs reduced in size and extend backwards and 

upwards ; a swimming fin usually not developed : 2 families, both marine. 

Key to the families of Anomura: 

Ox Animals burrow In the sand 1. Hippidae 

a, Animals live in snail shells ; hermit crabs 2. Pagukidae 

Family 1. HIPPIDAE. 

Cephalothorax cylindrical, with the abdomen bent under it; telson 
triangular and elongate; first pair of periopods not chelate: 3 genera and 
about 20 species, which burrow in the sand. 

Hipp a Fabrieius. Second antennae long and fringed, with long hairs 
on its hinder surface; eye stalk very long: 2 species, 1 American. 

a. talpoida Say. The sand bug (Fig. 626). 
Length 25 mm.; color whitish tinged with purple on 
tbe back: Cape Cod to Florida; Pacific coast; very 
common on sand bottoms and beaches, in which it 
burrows with great rapidity. 

Family 2. PAGTJBIDAE. 
Hermit crabs. Cephalothorax flattened, and with 
a hard shell; abdomen usually asymmetrical, elon- 
gate, and soft; eye stalks long; first pair of periopods mppa wipoi&a 
large and chelate, last pair reduced in size and extend- 
ing backwards and upwards, abdominal appendages rudimentary or 
wanting, the last pair used to hold the animal in the snail shell in which 
it lives. Allied to the hermit crabs is one of the most remarkable terrestrial 
decopod crustaceans, Birgus latro, the palm crab of the Pacific. It lives in 
holes in the ground and seldom goes into the water, but breathes air, the gill 
chambers being converted by the presence of a network of blood capil- 
laries into lungs, while the gills are 
very small. Its food consists of cocoa- 
nuts, which, however, it does not climb 
the trees to get, as it is popularly 
supposed to do. The family contains 
about 20 genera. 

PAGiraus Fabricins. First pair of 
antennae short, second pair long; right 
claw usually tbe larger: the animal 
lives in the empty shell of some marine 
snail which it carries about with it, and 
as it increases in size changes for a 
larger one; the shell is frequently more or less covered with colonies of 
a hydroid, Hydractittia eehinala, with which it lives in commensaKsm, 
the hydroid enlarging the shell by building up its free edge and thus 
saving the crab the necessity of changing its abode; over 100 species. 
P. longicarpuB Say. Small hermit crab. Chelae smooth and elon- 
gate: very common from Maine to South Carolina, usually inhabiting the 
shells of small snails iu rock pools and shallow water along the beaeh. 


P. poIHcaris Say (Fig. 627). Large or warty hermit crab. Chelae 
covered with tubercles, and very wide and stout, and used by the animal 
to close the opening of the shell: Maine to Florida, usually inhabiting 
the shells of Fulgttr, Nation, or other large snails in deeper water along 
the shores. 

Suborder 2. BRACHTURA. 

Crabs. Cephalotborax short and broad, with the small abdomen 
bent under it; abdomen of the male very narrow, with rudimentary legs 
and fitting into a groove of the ventral surface of the cephalotborax; 
abdomen of the female broad, with 4 pairs of well-developed biramose 
legs to which the eggs are attached ; antennae very short and often foot- 
like; third pair of maxfllipeds fiat and plate-like and covering the other 
mouth parts; the 5 pairs of periopods well developed, the first pair form- 
ing the large pinching claws; the abdominal legs much reduced, from 1 to 
4 pairs being present; no 
uropods present; young usu- 
ally born in the zoom stage 
and pass through the mega- 
lopa stage before reaching 
maturity (Fig. 628). 

The crabs are the high- 
est crustaceans. They occur 
mostly in the sea, living on 
B or near the bottom, from tide 

iuiO. A, lore*; |; ne8 to yerv g rea t depths, 

Some, however, like the blue 
crab, swim very well and rapidly and are frequently seen near the 
surface. Some species, like the fiddler crabs and the sand crabs, live 
near the high-water line or above it and have become to a greater or 
less degree terrestrial animals. They run about rapidly over the sand, 
in which they dig deep burrows, and their gills and gill chamber are 
especially adapted to the absorption and retention of moisture from 
the damp sand. Still other crabs, as those belonging to the Gecarci- 
nidae, the land crabs which are often distinguished by their large 
size, are found habitually far from the water, to which they return period- 
ically to deposit their eggs. Cardtsoma guanhumi, the common land crab 
of the West Indies and Bermuda, occasionally makes its appearance in 
Texas. The crabs of the family Thelphuaidae live exclusively in fresh 
water, the best-known representative being Thelphusa fluviatilis, the com- 
mon fresh-water crab of southern Europe. The suborder contains 4 


Key to the divisions of Brachyura here described: 

a x Carapace more or less triangular, being narrow in front. . . .1. Oxybhyncha 
o, Carapace more or less circular, elliptical or rectangular, with a wide- 
arched or straight front margin. 

bx Carapace elliptical, with an arched front 2. Cyclometopa 

6, Carapace rectangular, with a straight front margin 3. Catomktopa 

Division 1. OXYBHYNCHA.* 

Carapace usually narrow and triangular in front and broad and 

rounded behind; 9 pairs of gills; first antennae longitudinally folded: 

3 families. 

Family MAIIDAE. 

Carapace narrow in front, rounded and broad in the middle, taper- 
ing anteriorly to the prominent rostrum, which may be bifurcate: about 
34 American genera, all marine and littoral and occurring principally in 
southern waters ; some of the species have the habit of concealing them- 
selves by placing on their backs with their pincers, algae, sponges, etc., 
which often grow there. 

1. Libihia Leach. Spider crabs. Eyes can be retracted into orbits, 
which conceal them; rostrum bifurcate; body covered with a dense 
growth of chitinous hairs which give it a furry appearance; it may also 
have growing on it hydroids, algae, worm 

tubes, etc., which tend to conceal it : 6 species. 

L. emarginataf Leach (Fig. 629). Cara- 
pace evenly rounded behind and with 
spines on the back, 9 of these being median 
in position; legs long, the chelipeds in the 
male being very long; length of carapace 7 
cm.; breadth 6 cm.: Atlantic coast from 
Maine to Florida, very common on mud Fl * ^^j^Z*)!*"**™ 
fats and oyster beds. 

L. dubia Milne-Edwards. Like the above, but with fewer spines on 
the back, 6 of which are median: Cape Cod to Florida; less common than 
L. emarginata. 

2. Htas Leach. Carapace more or less triangular; rostrum bifur- 
cate, the 2 branches converging, eyes in orbits but not completely con- 
cealed: 3 species. 

H. coarctatus Leach. Toad crab. Lateral edges of carapace dilated 

• See "Catalogue of the Crabs," etc., by Mary J. Rathbun, Proc. U. 8. Nat. Mus M 
Vol. 15, p. 231, 1892 ; also Proc. U. 8. Nat. Mas., Vol. 16, p. 63, 1893. "Synopsis of 
the Oxyrhynchoas and Oxystomatoas Crabs of North America," by Mary J. Rathbun, 
Am. Nat., Vol. 34, 1900. 

f See "On the Anatomy of Llbinia emarginata," by B. A. Andrews, Trans. Conn. 
Acad., Vol. 6, p. 99, 1884. 


anteriorly; length of earapace 8 cm.; width 6.4 cm.: Greenland to Vir- 
ginia; Europe; North Pacific; in 5 to 1,000 fathoms. 

3. Pell* Bell. Carapace triangular, and much longer than broad; 
surface smooth; eye stalk in an orbit but not completely concealed: 2 
American species. 

P. muttca (Gibbes). Small spider crabs. Claw of male with nearly 
parallel sides and with edges which meet only at the tip: Cape Cod to 
Florida and the Gulf of Mexico, from low-water mark to 15 fathoms. 

Division 2. CYCLOMETOFA.* 
Carapace more or less circular or elliptical in form and usually 
broader than long, the front forming a regular arch, and without a 
distinct rostrum; 9 pairs of gills present: 6 families. 
Key to the families of Cyelometopa here described : 

a, Fimt antennae folded longitudinally or nearly so 1. Cakckidac 

(i, First antennae folded transversely or obliquely. 

Oi Last pair of less not flattened tor swimming 2. Ptlumnioak 

b. Last pair of less flattened for swimming 3. Fobtunidae 

Carapace usually broader than long and with very short rostrum 
or none at all; anterior margin arched and serrate; last pair of legs 
pointed at the end : about 4 genera. 

CaJtOXa L. Carapace flattened, and more or less elliptical in shape; 
the outer maxillipeds completely cover 
the other mouth parts: 11 American 
species, 2 on the Atlantic coast. 

0. Irrorattu Say. Rock erab (Fig. 

630). Anterior margin of carapace 

with 9 blunt teeth on each side; length 

of carapace 7 cm.; breadth 10 em.; 

color yellowish, thickly spotted with 

Bmall reddish dots: Labrador to South 

"*■ "^aSZu^"" Carolina; common among rocks and 

in the sand, in which it may lie buried, 

from low water to 300 fathoms ; the commonest crab on the New England 

coast, where it is occasionally used for food. 

0. borealis Stimpson. The northern or Jonah crab. Similar to the 
preceding but larger, with a more convex and much rougher carapace; 
color brick red : Labrador to Connecticut, often common among the rocks 
in exposed places, not living under the rocks or in the sandy or muddy 

* Bee "Hynopils of the Cyclometopous or Cancroid Crsbi of North America," by 
Mary I. Rathbon, Am. Nat, Vol. 31, 1900. 


0. magister Dana. The edible crab of California. Carapace 12 
cin. long and 15 cm. wide, with 9 short spines on each side of the anterior 
margin; color reddish-brown: common below low-water mark on the 
entire Pacific coast, where it is used for food. 

Family 2. PILT7MNIDAE. 

Small dull-colored crabs with the first antennae folded transversely 
or obliquely, with a nearly round cephalothoraz and without swimming 
periopods: about 15 American genera, mostly southern. 

Pavopeto* Milne-Edwards. Mud crabs. Carapace slightly broader 
than long : small, inconspicuous crabs which live on muddy bottoms along 
the shore, often on oyster beds in brackish water, or even in fresh water; 
about 14 American species. 

P. (Neopanopeus M.-Ed.) sayi S. I. Smith (Fig. 631). Carapace 
somewhat convex, with a dentate anterior border; male abdomen with 
the terminal segment triangular and somewhat broader than long; 

Fig. 681 Fig. 632 Fig. 633 

Fig. 631 — Panopeus sayi (Paulmeier). A, dorsal aspect; B, male abdomen. 
Fig. 632 — Panopeus depress** — male abdomen (Paulmeier). Fig. 633 — Panopeus 
herbstl — the large claw (Benedict). 

length of carapace 17 mm.; breadth 22 mm.; color dark and dull: Massa- 
chusetts to Florida; common. 

P. (Eurypanopem M.-Ed.) depresses Smith (Fig. 632). like 
P. sayi but with a flatter carapace and with a terminal abdominal seg- 
ment in the male which forms an equilateral triangle, with arched sides; 
length of carapace 14 mm.; breadth 19 mm.: Cape Cod to Florida. 

P. herbsti M.-Ed. (Fig. 633). Carapace with a dentate anterior 
border and with a tubercle just beneath the first tooth; the larger claw 
with a stout tubercle at the base of the movable segment; terminal 
abdominal segment in male rounded ; length of carapace 40 mm. ; breadth 
60 mm.: Long Island Sound to Florida; near high-water mark. 

Family 3. POBTUN1DAE. 

Swimming crabs. Carapace broader than long and with a well- 
defined serrate, anterior margin; the last pair of periopods broad and 

* See "The Genus Panopeus," by James B. Benedict and Mary J. Hathbnn, Proc. 
U. 8. Nat Mu*., Vol. 14, p. 365, 1891. 


flattened at the end, and except in Carcinides mamas not pointed, forming 
effective paddles: 7 American species. 

1. Om JlH r tM * Stimpsoii. Carapace about twice as broad as long, 
the anterior margin forming a serrated arch, at each end of which is a 
long, sharp spine: about 4 species on the coast of the southern states. 

0. sapidu Rathbnn (C. hasta 
tus Say). Bine or edible crab 
(Fig. 634). Length of carapace 7 
cm.; breadth 13 cm.; color dark 
green; feet bine: Cape Cod to Lou- 
isiana, common on muddy bottoms 
in shallow, brackish or even fresh 
water, often swimming among sea- 
weed or near the surf ace; next to 
HI*. «3i— CatHnectet taptdut (Rathbnn). tbe lobster our most important 
food crustacean. 

2. OvaLlPEB Rathbnn (Piatyonichua Latreille). Carapace not very 
broad, being almost round, with 5 acute teeth on each side of the 
anterior margin; 1 species. 

0. oceUatus (Herbst). Lady crab (Pig. 635). Length of carapace 
5 cm.; breadth 6 cm.; color light with red spots: Cape Cod to the Gulf 
of Mexico, on sand beaches; is used for food in the South. 

3. Oahcihideb Rathbun (Carcimu Leach). Carapace slightly 
broader than long; chelipeds rather short; last pair of thoracic feet flat- 
tened but with pointed tips: 1 species. 

0. Tjusnaa (L.). Green crab (Fig. 636). Carapace with 5 large, 
acute teeth on the forward margin on each side; length 4 cm.; breadth 
5 cm.; color green, mottled with yellow: Cape Cod to New Jersey; 
Europe, where it is used for food; among the rocks in shallow water; 
breeding season in spring. 


Division 3. OATOMETOPA.* 

Carapace more or less rectangular, with a wide, straight ante- 
rior margin and a straight but narrower hinder margin ; no rostrum pres- 
ent: 4 families, including the land and strand crabs, which are among 
the most active and intelligent crabs. 

Key to the families of Catometopa here described : 

Gi Carapace soft and membranous ; in oyster or mussel shells. 1. Pinnothebidae 
a, Carapace hard and firm 2. Ocypodidae 


Carapace nearly circular and more or less membranous; eye stalks 
very small: small crabs, the females of which live in the mantle cavity 
of certain pelecypods or in annelid tubes, the males being 
free-swimming; 1 genus. 

Pzhhothsbes Latreille. With the characters of the 
family: several species. 

P. ostreum Say. Oyster crab. Surface of body pSSkSSret 
smooth and shiny; length and breadth of carapace about Tv^rim* 
5 mm.: in the mantle cavity of the oyster. 

P. maculatng Say. Mussel crab (Fig. 637). Surface hairy; length 
and breadth about 8 mm. : in the mantle cavity of Mytilus edulis and other 
bivalves, from Cape Cod to South Carolina. 

Family 2. OCYPODIDAE. 


Carapace broad anteriorly and more or less quadrangular; eye stalks 
long, each lying in an elongated groove-like orbit : 6 American genera. 

1. OcYFODEf Fabricius. Carapace square in shape, with distinct 
lateral margins ; chelipeds small, somewhat unequal ; other periopods flat, 
with pointed tips; eye stalks stout: 1 American species. 

0. albicans) Bosc (0. arenaria Say). Sand crab. Length of carapace 
30 mm.; breadth 35 mm.; chelipeds of nearly the same size in both sexes; 
claw with serrated margins : New Jersey to Florida and southwards, living 
in deep burrows above high- water mark; a very active crab which has 
become a terrestrial animal. 

2. XJoa§ Leach (Gelasimus Latreille). Fiddler crabs. Chelipeds of 
male of very unequal size, one, usually the right, being enormously devel- 

• See 'The Catometopous or Grapaoid Crabs of North America/' by Mary J. 
Rathbun, Am. Nat., Vol. 34, p. 583, 1900. 

t See "Cardiological Notes, No. Ill, Revision of the Genus Ocypoda," by J. 8. 
Kingsley, Proc Acad. Nat. 8ci., Phil., for 1880, p. 179. 

J See "Habits, Reactions, and Associations in Ocypoda arenaria," by R. P. 
Cowles, Monograph No. 103, Cam. Inst, of Wash., 1908. 

| See "Cardnologlcal Notes, No. 11, Revision of the Gelasiml," by J. S. Kingsley, 
Proc Acad. Nat ScL, Phila., for 1880, p. 135. 


oped and carried across the front of the body; eye stalks very long and 
slender; color light brown, mottled with purple and dark brown: small, 
active crabs, living in burrows, often a foot or two deep, in salt marshes 
and on mud and sand flats; they are frequently seen in large droves, and 
have the habit of slowly waving the large claw back and forth, probably 

a threatening attitude; numerous species; cos- 
mopolitan; about 7 American species. 

U. pugnax (S. I. Smith). Inner surface of 
large claw with an oblique ridge, beneath which 
are granules; length of carapace 15 mm.; width 

Fig. fgs—Uoa mtaa* 23 mm.: Cape Cod to Florida; common in salt 
(Pauimeler). * ' 


XJ. minax (Le Conte) (Fig. 638). Legs with red patches at the 
articulations; large claws with an oblique ridge on the inner surface; 
length of carapace 25 mm.; width 38 mm.: Cape Cod to Florida; the 
largest of the fiddlers, common in salt marshes, usually farther from 
the sea than the other species, being frequently where the water is 

XJ. pugilator (Bosc). Length of carapace 15 mm.; width 21 mm.; 
inner surface of large claw without oblique ridge: Cape Cod to Florida, 
on sandy or muddy beaches near high-water mark. 


Arthropods without antennae, in which the body is usually made 
up of two divisions, the cephalothorax and the abdomen, the former rep- 
resenting the fused head and thorax and bearing six pairs of appendages, 
and the latter being in most cases without appendages. The class con- 
tains 2 subclasses. 

Key to the subclasses of Arachnoidea: 

Ox Marine arachnoids of large size, with appendages bearing gills on the 

abdomen, and a long spike-like telson .1. Xiphosuba 

o, Mostly terrestrial arachnoids without abdominal appendages. .2. Arachnid* 

Subclass 1. XIPHOSURA. # 

King or horseshoe crabs. Large crab-like arachnoids, in which the 
body consists of a cephalothorax, an abdomen, and a long spike-like tel- 
son or tail. The cephalothorax is horseshoe-shaped and unsegmented 
and with an arched dorsal surface, in the center of the ventral surface 
of which is the mouth. Six pairs of elongate appendages surround the 
mouth, the anterior five of which are chelate, the sixth pair terminating 

• See "Xiphosora," Camb. Nat. Hist, Vol. 4. p. 259, 1909. 


with a number of movable projections called the pushers, because they 
are used by the animal in pushing itself through the sand and mud. The 
first pair lie in front of the mouth, and are called the mandibles or 
chelicerae: they are much smaller than the others, but have the same 
shape. The basal joints of the remaining five pairs of legs are spiny 
and assist in chewing the food. The abdomen bears six pairs of appen- 
dages, none of which are leg-like. The first pair are called the operculum 
and form together a broad plate which falls over and covers the remain- 
ing five pairs ; these are also plate-like and bear on their hinder surfaces 
numerous thin gills. The males are smaller than the females and differ 
from them in the structure of the second pair of appendages, the claw of 
which is a thickened structure, of use in holding on to the shell of the 
female while pairing. The paired genital openings are at the base of the 
operculum. The telson may be as long as the rest of the body. 

The dorsal surface of the cephalothoraz bears two large lateral com- 
posite eyes and a pair of small median ones. The dorsal surface of the 
abdomen is flattened and bears a row of movable spines on each lateral 
edge. The internal anatomy is essentially arachnid in character.* 

The king crab lives in shallow water along the shore, where it bur- 
rows in the sand and mud and eats worms and other small animals. It 
comes to sandy beaches in the early summer to breed, and lays its eggs 
in depressions it makes in the sand. The embryo as it emerges from the 
egg has a resemblance to a trilobite and lacks the spine-like telson and 
the abdominal appendages. The animals, although of large size, have 
little economic importance. They are, however, sometimes fed to chick- 
ens and pigs. 

History.— The American Limulus was first made known in 1590 by 
Thomas Harriot in his description of the animals and plants of Virginia. 
The Asiatic species became known during the 17th century, the dried shells 
having frequently been brought to Europe as curiosities. Until quite 
recently zoologists have placed Limulus among the crustaceans. Latreille, 
however, in 1808 called attention to its peculiar structure and created for 
it the separate order Xiphosura, and Straus-Diirckheun in 1829 empha- 
sized its resemblance to arachnids. This idea, however, gained ground 
very slowly, although Huxley and von Beneden both spoke in favor of 
it, and it was not until after Lankester's demonstration in 1881 that 
Limulus was finally accepted as an arachnid, f Another question of rela- 
tionship with which Limulus has to do is whether the primitive arachnid 

• See "The Embryology of Limulus," by J. 8. Kingsley, Jour. Morpb., Vol. 7, p. 
35, and Vol. 8, p. 105, 1802-3. "Studies on Limulus/' by W. Patten and W. A. Reden- 
baugb, Jour. Morpb., Vol. 16, p. 1 and p. 91, 1900. 

t See "Limulus an Aracbnid," by B, R. Lankester, Quart. Jour. Mic. Scl., Vol. 
21, 1881. 


group from which it sprang is allied to the vertebrates and thus may be the 
ancestor of this important class, as is maintained by Patten and others." 

The subclass contains the single genns Limulus. A few years ago, 
however, a new classification was proposed subdividing this genus into 
three, which were grouped in two subfamilies: this classification has not 
been generally adopted. 

Lnruxroi 0. F. Hiiller. With the characters mentioned : 5 species, 
of which 4 inhabit the eastern coast of Asia and its islands. 

10, operculum ; : 

I,. Polyphemus (L.) (Fig. 639). Length up to 50 em.; color dark 
brown: eastern coast of North America from Nova Scotia to Florida; 

Subclass 2. ARACHNIDA. 

With rare exceptions air-breathing, terrestrial animals, without 
antennae and with a body consisting of a cephalothorax and an abdomen. 

External Structure.— The cephalothorax bears six pairs of appen- 
dages, the mandibles or chelicerae, the pedipalps, and the four pairs of 
walking legs. The abdomen is without locomotory appendages. The boun- 
dary between these two body divisions is usually distinct, but in the mites it 
is obliterated. In the spiders as well as the mites segmentation has 
mostly disappeared and the body is short and compact. In contrast to 
these forms are the scorpions, in which the body is long and vermiform, 
with distinct segmentation. In the Solpugida the head is distinct from the 
thorax and bears the first three pairs of appendages. The mandibles 

* Sec "The Evolution of the Vertebrates and Their KID," by W, Patten, 1818. 


are short and end, on each side, either in a sharp, piercing claw, as in 
spiders, or in a pincer-like claw, as in scorpions. The pedipalps are usually 
sensory in function, but are prehensile organs in scorpions and many other 
arachnids, and in the male spider have a copulatoiy function. The four 
remaining pairs of appendages are locomotory and are usually long and 
slender. The abdomen in the embryo has often rudimentary appendages, 
the hinder three pairs of which in the spider become the spinnerets. 

The cuticula of arachnids is often covered with cuticular hairs or 
scales, which have often an important tactile function. The special 
sense organs are not well developed. Eyes are generally present, but 
they are ocelli and not the composite eyes so characteristic of other 

Internal Structure (Fig. 654).— The digestive tract is often of com- 
plex structure. Long diverticula may extend from the stomach towards 
or into the legs, and a network of diverticula in the form of the so-called 
liver usually occupies & large part of the abdomen; one or more pairs of 
Malpighian or kidney tubules enter the rectum. 

The respiratory organs are wanting in some mites and other minute 
arachnids, but are usually present in the form of lungs and tracheae. The 
lung is a ventral sac, usually near the anterior end of the abdomen and 
opening to the outside through a pore called a spiracle, which contains 
numerous leaf-like plates like the leaves of a book, in which the blood 
circulates. The tracheae are air tubes reinforced on their inner surface 
by a cuticular lining usually in the form of a spiral thread to keep them 
from collapsing, which extend from spiracles throughout the body. 
Scorpions and some of the larger spiders have only lungs; most spiders 
have both lungs and tracheae; and mites and many other arachnids have 
only tracheae. 

Circulatory organs are wanting in many arachnids which lack a 
special respiratory apparatus, but in most of them a tubular heart with 
lateral valvular openings is present in the abdomen, from the ends of 
which arteries extend into the surrounding organs. The Tardigrada are 
hermaphroditic, but with this exception all arachnids are unisexual. The 
paired gonads lie in the ventral portion of the abdomen and open to the 
outside by paired ducts or by a single duct in the first or second abdomi- 
nal somite. The sexes may often be distinguished by their external 
characters, the male being smaller than the female and often provided 
with special copulatoiy organs. 

Most arachnids are oviparous, but the scorpions and a few others 
bear their young alive. The young usually resemble the parents in 
appearance, but in a few cases, as in the Linguatulida and the mites, 
they go through a metamorphosis. The great majority of arachnids are 


predacious or parasitic animals, but a certain number of them, including 
many mites, feed on plants. All of the Linguatulida and about half of 
the species of mites are parasitic. Most arachnids are terrestrial but 
the Tardigrada, Pygnogonida and two families of the Acarina are 

History.— The name Arachnida originated with Lamarck in 1801, 
who at that time separated these animals from the Insecta aptera of Lin- 
nffius and his immediate followers. The subclass contains about 20,000 
species grouped in 11 orders. 

Key to the orders of Arachnida: 

Ox Abdomen distinctly segmented. 
&i Animals not parasitic. 

Ox Long segmented postabdomen or segmented caudal filament (except the 
Tarontulidae) present. 

d L Postabdomen with caudal sting present 1. Soobpionida 

dt Caudal filament (except the Tarantulidae) . 
ei Animals minute; caudal filament with segmental bristles. .2. Palpighaoi 
e, Animals larger ; caudal filament, when present, smooth. . . .3. Pedipalpi 

c, No postabdomen or caudal filament. 
dx Head distinct from thorax, bearing first 3 pairs of 

»f x^l appendages 4. Solpuoida 

d, Head not distinct. 
/ ''/"^^S^s— €l ^dliwrtp 8 chelate and very long. 


c, Pedipalps not chelate ; legs very long and Blender. 

o, Animals worm-like and internal parasites in 

vertebrates 9. Linguatulida 

a, Abdomen not segmented. 

o t Animals usually terrestrial. 

j/ ij c x Cephalothorax distinctly separated from abdomen . 

7. Abaneae 

c, Cephalothorax and abdomen not distinct. . . .8. Acarina 

6, Animals aquatic. 

t c, Animals microscopic 10. Tabdiohadi 

* c a Animals marine and not microscopic; legs very 

Pig. 640— Dia- i ong a nd slender 11. Pycnooonida 

gram of the dor- 
sal aspect of Cm- . m 

trurus (Banks). ORDER 1. SOOBPIONIDA.* 

1, cephalothorax ; 

postobdomenT V (Fig. 640.) Elongated arachnids with a short, un- 

pedipaips ; 6, lat- segmented cephalothorax and a long abdomen consisting 

median 6 eyes; 8,' of 13 segments, of which the anterior 7 form the pre- 

splne; 9, s ng. a |^ omen j^^ are aDO ut of the same diameter as the 

cephalothorax, and the posterior 6 form the much narrower, tail-like post- 
abdomen, at the end of which is a poisonous sting; 3 to 6 pairs of eyes 
usually present; mandibles short and chelate; pedipalps very long and 

• See "Scorplones und Pedipalpi," by K. Kraepelln, Das Tierreich, 1899. "Synop- 
sis of the North American Scorpions, Solpuglds, and Fedlpalpl," by Nathan Banks, 
Am. Nat, Vol. 34, p. 421, 1900. 

SC0BPI0N1DA 405 

chelate; on the ventral surface the second abdominal segment bears a pair 
of long comb-shaped appendages called ihe pectines, which probably aid in 
the act of pairing, following which are 4 pairs of spiracles, each of which 
opens into a lung sac; genital opening just in front of the pectines on 
the first abdominal segment and protected by small paired plates, which 
form the sternum; the young are born alive and are carried about for 
a while by the mother: over 300 species, about 25 occurring in our south- 
ern and western states, ranging as far north as Nebraska; they are 
nocturnal animals and feed on insects and spiders which they often 
kill with the sting. 

Key to the families of Scorpionida here described: 

a x Sternum broad, pentagonal ; usually no spine under the sting. 

bi At base of terminal segment of last pair of legs at least 1 spur on inner 

and 1 on outer side 1. Vejovidak 

b 9 But 1 spur present, on outer side 2. Scorpionidab 

o, Sternum long, triangular ; usually a spine under the sting. . .3. Centbustdab 

Family 1. VEJOVIDAE. 

Three eyes on each side; terminal joint of legs with an inner and 
outer spur at base; no spine under the sting: 8 genera and 18 species. 

1. Vejoyis Koch. Median lamella of each comb divided into at 
least 8 small pieces; lower margin of the movable finger of mandible 
without spines: 6 American species. 

V. boreus (Girard). Hand strongly keeled; color yellowish or 
greenish: Nebraska and westerly to Nevada and Idaho. 

V. mexicanus Koch. Hand less distinctly keeled; color brown, not 
spotted; legs reddish; length 8 cm.; number of teeth of comb 15 to 22: 

V. carolinus Koch. Color reddish-brown; legs yellow; length 34 
mm. ; number of teeth of comb 13 or 14 : southern Atlantic states and into 
Kansas and Texas; California. 

2. Hadbtous Thorell. Large, hairy scorpions with a large, dark 
spur near the tip of the lower margin of the movable finger of the man- 
dible: 2 species. 

H. birsutus (Wood). Color yellowish-red; length 7 cm.; number of 
teeth of comb 25 to 40; legs compressed: California and Arizona. 


Sternum pentagonal in shape; but 1 spur at the base of the last 
tarsal joint, which is on the outer side; usually no spur under the sting: 
15 genera and about 88 species. 

DiPLOOSif T&TT8 Peters. With a hump under the sting : 6 species, all 



D. whitei (Gervais). Color yellow or brown; terminal joint of foot 
with a row of about 7 spines running up from the claw; teeth of comb 
12 to 18; length 5 cm.: Texas to California. 


Sternum small and triangular, the sharp end in front ; a spur on the 
nnder side of the unmovable finger of the mandible : 4 genera and about 
50 species, many American. 

Gehtbtotxs Ehrenberg (Fig. 640). The oblique rows of teeth on 
the finger of the pedipalp have on each side a parallel row of minute 
teeth; under the sting may be a spine: 15 American species. 

0. caroliniantu (Beauvois). Color yellowish, with small spots, often 
joined into 2 longitudinal stripes ; length 7 cm. ; teeth of comb, 19 to 25 : 
southern states. 


Minute arachnids with a segmented abdomen, from the hinder end 

of which a long segmented caudal filament 
with segmental bristles projects; mandible 
long and chelate; pedipalps and the 4 pairs 
of legs rather long and slender; no eyes; 
cephalothorax of 3, abdomen of 11 segments : 
1 genus with a few species, which have 
been found in Italy, Siam, Paraguay, and 

Kcenenia Grassi. With the characters 
above mentioned: 2 American species. 

K. wheelerif Rucker (Fig. 641). Length 

with filament up to 2.5 mm.; color white; 

3 pairs of eversible lung sacs on segments 

w „ Am „ , .. , . 4 to 6: under stones in moist places near 

Fig. 641 — Kcenenia wheeleri r 

(Wheeler). Austin, Texas. 


Cephalothorax separated by a constriction from the abdomen, which 
is 11 or 12-jointed; last 3 pairs of legs used for walking; in the first 

• See "Palplgradi und Sollfugae," by K. Kraepelin, Das TIerreich, 1901. 

t See "A Singular Arachnid," etc., by W. M. Wheeler, Am. Nat., Vol. 34. p. 837, 
1900. "The Texas Koenenia," by Augusta Rucker, Am. Nat., Vol. 35, p. 615, 1901. 
"A New Kctnenia from Texas," by same, Q. J. M. S., Vol. 47, p. 401, 1903. 

t See "On the Pedlpalpl of North America," by H. C. Wood, Jour. Acad. Nat. Set., 
<Phila., Vol.' 5, p. 357, 1803. "Scorploncs und Pedlpalpl," by K. Kraepelin, Das TIer- 
reich, 1899. "Synopsis of North America Pedlpalpl," by N. Banks, Am. Nat, Vol. 34, 
p. 421, 1900. 



pair the terminal portion very much elongated and forming a long, 
many- jointed tactile flagellum; pedipalps thick and strong and, like the 
mandibles, either chelate or not; 2 pairs of book lungs on the third and 
fourth abdominal segments; 8 eyes usually present, 2 large ones in front 
and 3 small ones on each side; genital pores paired and on the first 
abdominal segment: predacious tropical animals, 5 species of which are 
found along the southern border of this country; 3 families and about 
CO species. 

Key to the families of Pedipalp* here described : 

o. Long filiform tail present 1. Thei.yphootdae 

o. No such tail 2. Taraktulidae 


Whip scorpions. Body elongate; pedipalps chelate; abdomen 12- 
jointed, the last 3 segments smaller than the others and bearing a long, 
jointed terminal filament and also often om- 
matoids, white ocellus-like spots: 10 genera and 
about 40 species. 

HatTisopBooTVB Pocock. Two ommatoids 
present: 17 species. 

M. giganteua (Lucas). Vinegar roan (Fig. 
642). Length (with tail) 13 cm.; color dark 
brown; tail with reddish hairs; animal has a 
strong odor of vinegar: Florida to Arizona, often 
common in dry sandy places; they are nocturnal 
Pig. «*2—MatUooproe- animals which are much feared, although they 

(m giganteui 

(Comstock). are not poisonous. 


Body broad, cephalothroax being broader than 
the abdomen and joined with it by a slender waist; 
pedipalp ends with a claw; abdomen 11 jointed and 
without a terminal filament: 10 genera and about 
IS species. 

Tarantula Fabricius. Foot with a single claw; 
front margin of eelphalothorax either with short 
teeth or smooth: i species, all American. 

T. whitei (Gervais) (Fig. 643). Front margin 
of cephalothorax denticulate; inner margin of pedipalp with long 
spines; color brown with a yellow margin; length 20 mm.: Texas to 


Taranliila VMM 


Obdeb 4. 80LPUGIDA.* (Solifcgak.) 

Head region separated from the thorax and bearing very large 
chelate mandibles, the leg-like pedipalps, and the first pair of legs, as well 
as a pair of eyes; thorax consists of 3 distinct segments, each bearing a 
pair of legs; abdomen 10-jointed; respiration by tracheae, the first pair 
of spiracles being on the thorax, the other 3 pairs being on the abdomen; 
genital pore in first abdominal segment: usually nocturnal animals which 
live in sandy deserts in the wanner parts of the earth; 3 families with 
about 165 species, a few of which are found in this country, chiefly in 
the southwest; they are much feared, although not poisonous. 

Second and third pair of abdominal spiracles not covered with 
denticulate plates: 21 genera and about 145 species. 

Esxhobatks Banks (Datamea Simon). 
Anterior margin of head truncate; fourth 
pair of legs without a terminal claw; dorsal 
finger of mandible without teeth or spar: 
about IS species, all in America. 

E. pallipes (Say). The movable seg- 
ment of the mandibles in the male with 1 
large and sometimes 1 very small tooth; 
the inner side of the pedipalp of male 
hairy and without bristles; length 13 mm.; 
color light yellow: southern states west 
of Mississippi, north into Kansas and 

Fig. 644 — Eremoiatc* Jarmi- CrArcmAn 

iabUi* (Kingsiey)/ Colorado. 

E. formidabllis (Simon) (Fig. 644). 
Movable segment of the mandible slender and with 1 large and 2 small 
teeth: California and Arizona. 

Order 5. P8EUD08C0RPI0NTDA.t 

Small arachnids with an 11 jointed abdomen, with chelate mandibles, 
the movable finger of which bears along its inner margin the comb* 

• See "The Bolpngldae of America." by J. D. Putnam, Proc. Darenport Acad. 
Nat Bd., Vol. 3, p. 1, 18S2. "Sj-iiopnii! of the North American Solpuglda" by N. 
Banka. Am. Nat. VoL 84, p. 436, 1900. "Palplgradl und 8ollfn*ae," by K. Kraepelln, 
Dae Tierrefch, 1901. 

t See "Note* on North American Chernetldac," by N. Bunks, Cand. Bntonu, VoL 
28, ISM.- "Notes on the Peendoacorplonldae," by N. Banka, Jonr, N. Y. Bntom. So*-, 
Vol. 3, 1893. "Habits and DUtribntlnna at the Pseudoacorplonldae, principally 
Chelanopa oblongna, Say," by K. W. Berger, Ohio Nat,, Vol. 6, p. 467, 1906. "A Lift 
of the North American Psendoecorplonlda," hj K. E. Coolldge, Psyche, VoL 16 a. 
108, 1908. 


shaped serrula (Fig. 645, B), and with long scorpion-like pedipalps; legs 
1° D £> 5- jointed, and ending with 2 claws; eyes present or not; respiration 
by tracheae, 2 pairs of spiracles being present on the second and third 
abdominal segments ; genital pore in the second abdominal segment, in the 
female surrounded by cement glands, the secretion of which serves to fasten 
the eggs to the body of the mother; silk glands open to the outside near tho 
tip of the movable finger of the mandible; the animals spin nests, in 
which they spend the winter or can retire during a moult; no poison glands 
present: under the bark of trees, among moss or dead leaves, or in 
houses, on old books, or furniture, where they eat mites and small insects; 
occasionally they attach themselves for purposes of migration to insects; 
they run rapidly forwards, backwards, or sideways; 3 families with 100 

Key to the families of Pievdoscorpionida here described: 
a, Cephnlothorai with a transverse suture ; two eyes or none usually 

present 1. Oheufebidae 

a. No such suture ; tout eyes usually present 2. Obisiidae 

Family 1. CHEL1FEBIDAE. 

Spinneret on mandible long and tubular; serrnla attached along its 
whole length; 2 eyes or none present: 5 genera. 

1. Okxiotb Geoffrey. Cephalothoraz triangular, rounded in front 
and divided by transverse sutures into 3 parts; 2 eyes present; man- 
dibles small: several species. 

0. cancroid es (L.). Book scorpion (Fig. 645). Length 3 mm.; color 
reddish-brown; dorsal abdominal plates divided by a median line; basal 

A 6 

Elf. 045 Fig. 040 

Fig. 645 — OhtHJer eancroUet. A, dorsal aspect (Lentils) ; B, mandible (Comatock). 
Els. 8*6 — Cheionopi oblongms (Berger). 

portion of pincer thick, terminal finger curved: often found in bouses 
on old books, furniture, or clothing; cosmopolitan. 

0. biserlatnm Banks. Body 2.2 mm. long, pale yellowish in color, 
with 2 rows of dark spots on tbe abdomen; pedipalps very slender; no 
large granules on cephalothoraz: Florida; Ohio; Jamaica. 


0. mnricattu Say. Body 2.5 mm. long and reddish-brown in color; 
hand of pedipalp very much darker than the rest: eastern states, among 
dead leaves. 

2. Ohslahops Nicole t (Chernes Menge). Similar to Chelifer but 
without eyes: about 19 American species. 

0. oblongus (Say) (Fig. 646). Body 3.5 mm. long, elongate and 
elliptical in shape, being widest in the middle, reddish-brown in color, 
being darker on the cephalothorax; a double row of large dark spots 
on the abdomen, from each of which a number of long bristles spring: 
widely distributed over the eastern and central states; under stones 
near low-water mark at Woods Hole. 

0. tristis Banks. Body 2 nun. long, pale reddish-yellow in color 
with soft parts and legs white; abdomen elliptical, the dark spots on 
the dorsal plates being much nearer the median than the lateral line: 
the seashore of Long Island. 

0. sanborni Hagen. Body 2 mm. long, very broad, and reddish- 
brown in color; pedi palps short and heavy with clavate hairs: eastern 
states, under bark. 

Family 2. OBISIIDAE. 

Spinneret a small knob; serrula attached only at the base; 4 eyes 
usually present: 4 genera. 

1. Obisiuh Leach. Cephalothorax rectangular and not narrower in 
front; pedipalps short and stout; 4 eyes present; fingers curved: 6 
species in America. 

0. muscorum Leach. Body 2.5 mm. long, brownish in color: in moss. 

2. Ohthontdb Koch. Cephalothorax rectangular and wider in 
front; mandibles large; fingers straight: about 5 American species. 

0. pennsylvanicus Hagen. Length 1.9 mm.; color brownish, with 
scattered silvery spots on the abdomen; legs white; pedipalps longer 
than the body; 4 eyes, not close together: eastern United States. 

Order 6. PHALANGHDA.* 

Harvestmen or daddy longlegs. Body short, ovoid in shape, with 
an unsegmented cephalothorax which is joined with the 9-jointed ab- 
domen without any constriction; mandibles chelate; pedipalps long and 
leg-like, each ending with a claw; legs usually very long and slender, the 
basal portion of the anterior pairs possessing chewing plates; the body 

* See "On the Phalangeae of the United States," by H. C. Wood, Common. Essex 
Inst, VoL 6, p. 10, 1868. "A Descriptive Catalogue of the Harvest Spiders (Phal- 
anglldae) of Ohio," by C. M. Weed, Proc. U. 8. Nat. Mus., Vol. 16, p. G43, 1893. 
"Synopsis of North American Phalanglda," by N. Banks, Am. Nat, VoL 35, p. Ml, 


of the male somewhat smaller and with longer legs than the female; 
a pair of simple eyes present, one being on each side of a tubercle rising 
in the middle of the cepbalothorax ; genital opening between the last 
pair of legs in a forward prolongation of the ventral plate of the first 
abdominal segment from which also extends a long protrusible penis or 
ovipositor (Fig. 648, 2) ; a pair of stink glands on the abdomen, which 
often become active when the animal is handled; respiration by tracheae, 
usually a single pair of spiracles being present on the first abdominal 
segment ; eggs laid in the gronnd or in other moist places in the summer 
or autumn and the young, which are like the adults in appearance, usu- 
ally hutch the following spring: 
. about 60 species in America, 
grouped in 7 families; animals more 
or less nocturnal, probably feeding 
principally on small insects, spiders, 
and mites, but also occasionally on 6 
decaying substances; they do not 
spin a web or build a nest. 

Key to the families of Phalan- 
giida here described: 

a, Last segment of pedipalp with o 

a terminal claw and longer * 

than Hip npwwlinf raiP F1 £- 0*T— A, rtornal Tiew of a pha- 

tnan me preceding one. langld; B, ventral view of a pnalangid 

1. PhaLaNQIIDAE (Itankn). 1, mandibles; 2, pedipalps ; 

«, No .uch A.W .»d tb, 1.M «r SBSilte TKuUf 'A~ "" hfi 

meat much shorter than the ward prolongation or abdomen; 9, 

preceding one . 2. NemastomaTipae spiracle; 10, anua. 

Family 1. PHALANQIIDAE. (Pio. 047.) 

Body ovoid with a leathery integument; pedipalp ending with a 
claw; legs long and slender, with a simple terminal 
1 claw on each: about 15 American genera. 

Key to the genera of Phalangiidae here de- 
uJjE'T?\ scribed : 

a, Eye tubercle of enormous utee 1. Caddo 

a. Eye tubercle of normal size 2. LiobUnUm 

6, Eye tubercle smooth. 
J b, Eye tubercle spinous S. PhalaNGIUH 

Fie. 648 — Caddo agttit 1. Oaddo Banks. Eye tubercle of enormous 

° 2, ovipositor? 1 '' size; 3 long spines on femur of pedipalp: one 
0. agiUs Banks (Fig. 648). Body 3 mm. long, brown in color, with 
2 pale stripes above: among dead leaves and moss. 



2. Liobuotx Koch. Anterior and lateral borders of cephalothorax 
not spinose; eye tubercle rather small and smooth; legs usually very 
long and slender: 16 American species. 

L. vittatum (Say) (Fig. 649). Body reddish- 
brown, with a distinct mid-dorsal stripe; pedipalps 
and legs brown or black ; length about 9 mm. ; of pedi- 
palps, 5 mm. long; length of legs, first, 42 mm., second, 

90 mm., third, 43 mm., fourth, 
61 mm.: eastern and central 
America; common in fields 
and woods. 

L. politnm Weed (Fig. 
650). Body reddish-brown; 
pedipalps light brown, legs 
black; eye tubercle rather 
prominent, with a row of small black projections over each eye; length 
about 5 mm.; pedipalps 2.8 mm. long; length of legs, first, 25 mm., 
second, 51 mm., third, 26 mm., fourth, 36 mm. : eastern and central states, 
in fields and woods; common. 

L. grande (Say). Body blackish and tuberculate, 9 to 12 mm. long; 
pedipalps 6 mm. long; length of legs, first, 20 mm., second, 35 mm., third, 
21 mm., fourth, 28 mm. : eastern and central states. 

Fig. 649 — Liobunum vittatum (Weed). 

Fig. 650 


Fig. 650 — Liobvnvm politum (Weed). A, dorsal aspect after tbe removal of the 
legs; B, side view of the eye tubercle. Fig. 651 — Liobunum ventricosum (Weed). 
A, dorsal aspect after tbe removal of the legs ; B, side view of the eye tubercle. 

L. ventricosum (Wood) (Fig. 651). Body elongate; legs and body 
cinnamon or yellowish-brown; length 7 to 10 mm.; length of legs, pedi- 
palps, 5 mm., first, 33 mm., second, 64 mm., third, 33 mm., fourth, 48 
mm.: eastern and central states; common. 

3. PHiXAYOlTOf L. Anterior and lateral borders of cephalothorax 
spinose; eye tubercle with 2 series of spines: 2 species in America. 



F. cinerenm Wood (Fig. 652). Body gray, sometimes brownish, 
usually with a wide lenticular mid-dorsal marking, and about 8 ram. 
long; pedipalps 4 mm. long; length of legs, first, 20 
mm., second, 52 mm., third, 29 mm., fourth, 36 mm.: 
northern America, on walls, etc,, rarely in the open 

Pedipalps long and prominent, with last joint 
much shorter than the preceding one and without a 
claw: 3 genera. 

Phlebkaokra Packard. Mandibles directed 
downwards and not forwards; fourth joint of pedi- 
palp much thickened; body somewhat compressed and 
not spiny: 3 species. 

P. cavicolons Pack. Body 4 mm. long and 2 mm. 
wide; eyes large and prominent; eye tubercle very 
low; a series of large 
transverse dark spots 
on back; movable 
finger of mandible 
with about 24 setae: ii 
places; eastern and central states. 

Order 7. AKANEAE." (Araneida.) 

Spiders (Fig. 653). Cephalotborax 
and abdomen mostly 
unsegmented and uni- 
ted by a slender waist. 
The body is often cov- 
ered with hairs or 
scales, and gray or 
dark in color when the 
animal lives on or near 
the ground, but is 
**** Often brightly colored 

when it lives on flowers, shrubs, or trees. Of the six pairs of appen- 
dages the mandibles or chelicerae are the most anterior; they are twc- 

• See "Catalogue o( the Described Araneae of Temperate North America," by Dr, 
George Man, Proc. U. S. Nat. Mim., Vol. 12, 18S9. "American Spldera," etc., by 
Henry C. McCook, 1889-1893. "Hlatolre Naturelle des Araigneea," t>7 B. Simon, Paris, 
1897-1904, 2nd Ed. "The Common Spldera of tbe United States," by Jamea H. 

Fig. 002 — Phalan- 

fWeed). A? 'dorsal 
aspect after tbe re- 
moval of the lega ; 

caves and similar 

male ( Warlmrtoul . 1, pedlpalp; 2, mandible: 3, max- 
illa ; 4, labium : S, lega ; 6, sternum ; 7, eplgynum ; 8, 
lung spiracle; 9, tracheal spiracle; 10, spinnerets; 11, 


jointed, the terminal joint being a sharp claw, near the end of which is the 
opening of a poison gland. The mdndibles are usually directed downwards 
so that the spider must strike when its prey is beneath it The second 
pair of appendages are the pedipalps or palpi, which are leg-like in form 
and composed of six segments; the large and flattened basal segments 
of these are called the maxillae or endites and extend forwards, forming 
the principal jaws of the animals, being used to chew or squeeze the 

In the male the end of the pedipalp is enlarged and bears the 
more or less complicated palpal organ by which sperm is conveyed to 
the female in the act of pairing (Fig. 653, C). The four pairs of long 
walking legs are seven-jointed. The tarsus or terminal joint of each leg 
bears a pair of claws, the inner edge of each of which is toothed ; in many 
spiders a third smaller claw is also present and in others a thick brush of 
hairs. Between the maxillae is a plate called the labium or lip, and 
between the base of the legs is the sternum. The abdomen bears at 
its hinder end, just in front of the anus, usually 3 pairs of spinnerets, 
which are modified legs (Fig. 655). At the end of each spinneret are 
minute tubes which are the ends of the ducts of the silk glands; the 
fluid silk coming out of these tubes unites to form a single strand, and 
hardens on exposure to the air. In a few families a plate called the 
cribellum lies in front of the spinnerets from which spinning tubes also 
project; such spiders have a row or comb of stiff hairs on each of the 
hind legs called the calamistrum (Fig. 655) by means of which a band of 
silk may be spun. All the spinning tubes do not exude the same kind 
of silk, but a variety of kinds is produced which are used for various 
purposes, as for making the different parts of the web, nests, cocoons, etc. 
Spiders are not well provided with special sense organs. The long 
legs and the hairs usually covering the body are tactile organs, and in 
most spiders eight simple eyes are present on the front portion of the 
cephalothorax usually in two rows, enabling the spider to see a short 
distance (Fig. 653, B). 

The respiratory organs of spiders consist of two pairs of lungs in 
the Tetrapneumones, which are situated in the forward part of the abdo- 
men and open to the outside by slit-like spiracles on the ventral surface; 
in the Dipneumones one pair of lungs is present and a pair of tracheae, 
the latter opening in most cases through a single spiracle in front of 
the spinnerets. Each of the lung spiracles is covered with an integu- 

Emerton, 1902. "Families and Genera of the Aranelda,*' by Nathan Banks, Am. Nat. t 
Vol. 34, p. 293, 1905. "Fanna of New England. A List of the Aranelda," by Eliza- 
beth B. Bryant, Boat Soc. Nat. Hist., Occ. Papers, No. 7, 1908. "Catalogue of Neartic 
Spiders," by N. Banks, Bull. No. 22, U. 8. Nat Mus., 1910. "The Spider Book," by 
J. H. Comstock, 1912. 


mental fold, and between them is the genital pore which, in the 
female, is covered by a plate, often complex in structure, called the 

The arrangement of the internal organs of spiders will be seen in 
the accompanying diagram (Fig. 654). 

Spiders prey principally upon insects, but will usually kill and 
devour any animal smaller than themselves, including their own kind. 
The female not infrequently eats the smaller male when he approaches 
her at pairing time. Spiders may be divided, as to their method of 
taking their prey, into 2 groups: (1), the hunting spiders, which run 
on the ground or on plants and spring upon their prey, usually from a 
concealed retreat, and (2), cobweb spiders, which make webs to catch 
flying insects. The hunting spiders often make nests of silk; the cob- 
web spiders usually live in their webs or in nests near them. 

The webs are of 4 kinds: (1), the very irregularly woven web of 

the bouse spider Theridion tepidariormn and other Theridiidae (Fig. 664) ; 

(2), the more or less 

irregular web of the 

Linyphiidae and some 

other spiders, the most 

important part of which 

consists of a large, flat 

or curved sheet held 

down by threads in all 

directions (Fig. 665) ; Fig. 804— Internal anatomy of a aplder (Shipley). 

,n\ .. i i l ■ 1. eyes; 2, poison gland: 3, moutli !_ 4, brain; 6, 

(3), the funnel webs of diverticulum of the stomach ; 8, lung : 7. genital pore ; 

.,,,., . , 8, silk glands: 9, anus; 10, spinnerets; 11, ovary; 

the Agelentdae, consist- 12, kidney tubule; la, intestine; 14, heart; iE, liver 

„ a . . , • ducts, the liver having been removed : 10. sucking 

ing of a flat sheet and stomach. 

a funnel leading to a 

retreat; (4) the round webs of the Epeiridac, composed of threads 

radiating from a common center, with cross threads (Fig. 667). 

Spiders lay spherical eggs which the female winds with silk into 
a spherical or oblong mass called the cocoon; this the spider often 
carries about for awhile in the mandibles or attached to the spinnerets, 
and fastens in the web or to grass or other objects, or hides in her nest. 
Some spiders construct burrows in the ground in which they deposit 
their cocoons. Spiders live usually less than a year. Great numbers, the 
adults of which die in the autumn on the approach of cold weather, pass 
the winter in the form of eggs, while others He torpid among leaves on the 
ground and in other protected places. Spiders are born with the form 
of the parent, but often differ from them at first very much in appear- 
ance; they are also sexually dimorphic, the males being smaller than 


the females, possessing the palpal organ, and often being differently 

Over 10,000 species are known, of which 1,300 belong in this country. 
The order contains 2 suborders and about 26 families. 

Key to the suborders of Araneae: 

a t Two pairs of lungs; usually 2 pairs of spinnerets; claw of mandible 

vertical in position 1. Tbtbapntumohes 

Oi One pair of lungs ; 3 pairs of spinnerets ; claw of mandible horizontal in 

position, working from the side, medially 2. Dipneuxones 


Often large spiders with 2 pairs of lungs and 2 or 3 pairs of spin- 
nerets; mandibles usually project more or less forwards, the claw of 
which projects downwards instead of transversely; with 8 eyes set 
closely together: tropical or subtropical spiders including the bird 
spiders and trap-door spiders; 3 families. 


Pedipalp arises near or at the tip of the maxilla, which is not dis- 
tinct; the 4 lung spiracles covered by broad and often glistening folds: 
40 American species. 

Paohylokekto* AusBerer. Trap-door spiders. Cephalothorax al- 
most as broad as long; abdomen ovoid; spinnerets 4; eyes close together, 
on low prominences, the lateral eyes being the largest; the extremities of 
the 2 hinder pairs of legs much thickened: 8 American species, in the 
southern states. 

P. audonini (Lucas). Length 20 mm.; the anterior lateral eyes 
the largest ; third joint of the third pair of legs very short and crooked ; 
color glossy brown: North Carolina; the animal lives in a cylindrical 
burrow in the ground lined with silk, the opening of which can be closed 
by a circular door which works with a hinge. 

Suborder 2. DIPNEUMONES 

Spiders with 1 pair of lungs; tracheae also present which open to 
the outside usually by a single spiracle; 3 pairs of spinnerets; mandibles 
directed downwards, the claws projecting from the side towards the 
median line: over 30 families. 

• See "A New Trap-Door Spider/' by G. F. Atkinson, Am. Nat., Vol. 20, p. 688, 


Key to the families of Dipneumones here described: 

Ox With cribellum and calamistrum (Fig. 655). 

b x Eyes all dark-colored (diurnal) ; web usually regular 1. Ulobohidae 

6, Anterior median eyes dark, the other light-colored (nocturnal) ; web 

Cx Lateral eyes near together 2. Dicttnidae 

c, All the eyes close together on an eminence 3. Filistattdae 

a% Without cribellum and calamistrum. 
b x Two terminal claws on the feet. 

c x Six eyes ; 4 spiracles ; ground spiders 4. Dtsdebidab 

c, Eight eyes present. 
dt Eyes usually in 2 rows. 
ex First 2 pairs of legs not noticeably longer than the others. 

ft Fore spinnerets widely separated ; ground spiders 5. Dbassidae 

f % Fore spinnerets contiguous ; ground spiders 11. Clubzonioae 

c, First 2 pairs of legs much longer than the others ; crab spiders. 

10. Thomisidae 
d x Eyes in 3 rows, the middle row being much smaller than the others. 

l % Three terminal claws on the last 3 pairs of feet. 15 - ATTn>AB 

c, Legs very long, being over 4 times the length of the body 6. Pholcidae 

c, Legs not so long. 
dx Eyes in 2 rows. 
€x Hinder part of spinnerets not very long. 

fx A comb of serrate bristles on the hind foot ; abdomen often globose. 
/, No such comb. 7 - Themdhdae 

g x Basal segment of mandible with row of teeth on its outer surface ; 

small spiders with irregular webs 8. Lintphudae 

g % No such mandibular teeth; usually large spiders with regular 

radial webs 9. Epeibidae 

g % A semicircular notch at base of leg on penultimate segment. 

13. Pisaubidae a i 

e, Hinder pair of spinnerets / 

very long and 2 jointed. 


<Z, Eyes in 3 rows. . .14. Ltcosidae /i 

Family 1. XJLOBOBIDAE. u *.-\ ^.^r^r- ~^7F? 

A cribellum and usually a cala- x " . Ajfl^xA j ft Cn\SSlBd)i 

mistrum (Fig. 655) present; lateral 3* jSmfi/^^^ 

eyes farther apart than the 2 pairs . ^^nptioWl 

of median eyes; web usually round f / g 

and regular, with radiating spokes Fig. 655— A, part of fourth leg of 

. . , i ., ^ j , Amourobius; B, ventral view of hinder 

joined by cross threads and com- end of same. l t calamistrum ; 2, cribel- 

~~,«j :„ «««* «4» i^yv«^ k«~;i„ ,** «:iu . lum ! 3 t anterior spinnerets ; 4, middle 
posed m part oi loose bands ot silk : spinnerets ; 5, posterior spinnerets ; 6 t 

3 genera, and 6 American species. anu8 - < c * mbriS *« Natural Hl8to ^> 
1. Ulobokto Latreille. Cephalothorax ovate, rounded behind; eyes 

all of about the same size: 4 American species. 

U. plumipes Lucas. Length of female 7 mm. ; cephalothorax low ; first 

pair of legs in the female twice as long as the second, with a bunch of long 

hairs at the end of the middle segment; color brown, with a median stripe 



on the cephalo thorax; male without the ealamistrum : common in shady 
woods and bushes, especially in the lower dead branches of pines. 

2. HTTTI0TE8 Walckenaer. Cephalothorax nearly circular, trun- 
cate behind; eyes of the posterior row very much 
larger than those of the anterior: 1 American species. 
EL cavatus (Hentz) (Fig. 656). Length of 
female 5 mm. ; abdomen ovoid, with 4 pairs of slight 
elevations covered with stiff hairs; color brown; web 
triangular in shape, with but 4 rays which radiate 
from a common strand held taut by the spider, and 
with cross strands : common, especially in pine woods. 

Fig. 656 — Web of 

Hyptiotes cavatus 


Family 2. DICTYNTDAE. 

With cribellum and ealamistrum in female but 

not in male; lateral eyes near together on each side; 

web irregular, usually a dense network of threads with a hole into which 

the spider retreats, found in open places: about 35 American species. 

1. Dictyva SundevalL Small spiders with sternum extending be- 
tween the hind legs; legs without spines; all the eyes of about same 
size ; head high arched, about half as wide as the thorax 

and distinctly marked off from it: numerous species, 
about 19 in America. 

D. snblata (Hentz) (D. muraria Emerton). Body 
gray in color, with dark median marking on the abdo- 
men, and about 3 mm. long; cribellum large: web on 
walls, fences, weeds, etc., often conspicuous because 
of the dust it collects; common. 

p. foliacea (Hentz) (D. volupis Keyserling). 
Body about 3 mm. long; cephalothorax brown; abdo- 
men yellow in the middle, and brown or red at the 
sides ; legs pale ; abdomen about as wide as the cephalo- 
thorax: web in bushes; common. 

2. Axattrobtus Koch. Sternum not extending between the hind 
legs; cribellum divided into 2 parts; head large and distinctly marked 
off from the thorax; legs with spines: about 7 American species. 

A. benneti (Blackwall) (A. sylvestris Emerton) (Fig. 657). Body 
10 mm. long; cephalothorax dark brown; abdomen gray with median 
yellowish markings; the epigynum has 2 lateral lobes which meet behind: 
web under stones and sticks; common. 

A. ferox (Walckenaer). Like above, but the lateral lobes of the 
epigynum do not meet behind: in houses, especially cellars; an European 
species introduced into this country. 

Fig. 667— a 
robins benneti 
(Bmerton). A, dor- 
sal aspect; B, male 
Id without 


Family 3. FILI8TATIDAE. 

With cribellum and calamistrum; all the eyes close together and 
upon an eminence; mandibles small; web like that of Bictyna: 1 
American species. 

Fzustata Latreille. With the characters of the family: 2 species. 

F. hibernalis Hentz. Body 12 mm. long with legs about twice as 
long, and uniformly dark gray in color: one of the commonest house 
spiders of the southern states. 

Family 4. DYSDER1DAE.* 

With only 6 eyes; with a pair of tracheal spiracles immediately 
behind the lung spiracles : the animals build tube-like nests on the ground 
under stones and other objects; 3 American genera and species. 

Dybdesa Latreille. Eyes in a ring, close together; mandibles long 
and inclined forward: 1 species. 

D. interrita Hentz (Fig. 658). Length 12 mm.; the 
abdomen but little larger than the cephalothorax ; color 
orange brown, lighter behind : New England. 

Family 5. DBASSIDAE.* 

Elongated spiders with 2 claws and a bunch of flat- 
tened hairs on each leg; eyes all of the same size, usually 
in 2 rows; spinnerets widely separated: ground spiders Dyi&era 
which build tube or sac-like nests ; about 60 American species. (Em extern) . 

1. Dbabsto Walckenaer. Eyes in 2 slightly curved 

rows, which diverge mid-dorsally, the posterior row longer than the 
anterior; mandibles small; maxillae straight: 9 American species. 

D. neglectus Keyserling (D. saccatm Emerton). Length 20 mm.; 
color light gray, without markings; abdomen but little longer than the 
cephalothorax: the animal lives under stones and makes a large trans- 
parent bag of silk in which the cocoon is deposited; common. 

2. Ghafhosa Latreille. Eyes in 2 nearly straight rows, the upper 
row longer than the lower; those of the middle pair of the upper row 
being much nearer each other than the lateral eyes : 10 American species, 

G. gigantea Keyserling (G. consperaa Thorell). Length 12 mm.; 
color rusty black; cephalothorax and abdomen of about the same size; 
mandibles large, with a wide serrate tooth under the claw: under stones 
and leaves. 

3. Seboiolus Simon. Maxillae arched around the labium; the 2 

rows of eyes nearly straight; no dorsal groove: 3 American species. 

* See "New England Spiders of the Families Drassldae, Agelenidae, and Dysderl- 
dae," by J. H. Emerton, Trans. Conn. Acad., Vol. 8, p. 1, 1800. 



8. variegatus (Hentz) (Fig. 659). Length 6 mm.; cephalothordx 
bright orange in color and smaller than the abdomen, which is black 
with 3 white stripes: on the ground. 

Family 6. PHOLCIDAE. 

Eyes either 6 or 8 in number; legs very long, with 
3 claws on each of the 3 hinder pairs: 6 American 
, _ genera. 

Pholotts Walckenaer. Three large eyes in a group 
on each side of the head and 2 smaller 
eyes in the middle; abdomen elongate; 
cephalothorax flat: 2 American species. 
b^mSs P - Pfcaiangioides (Fuesslin) (Fig. 

0Bmert£n*. 660 )' Bod 3 r 6 mm ' lon Z'> lon S^^ kg* 5 

cm. long; color pale brown or gray: a 

common house spider both in America and in Europe, 

living in cellars, and making a large, flat, irregular web. 

Family 7. THEBIDIIDAE.» 

Usually small, light-colored spiders with a large 
round abdomen ; eyes of about the same size, in 2 rows, pfciSS? 

with the end eyes near together and the middle eyes phatongioidee— 

carrying its 

farther apart; outer margin of mandibles parallel (ex- egg sac 

cept on Steatoda) ; 3 claws on each leg : web often large, 

more or less irregular in form and loose in texture, and built in the cor- 
ners of rooms, on fences and rocks, and between the branches of low 
trees and bushes, the spider usually staying in the web; about 300 
American species. 

Key to the genera of Theridiidae here described : 

Ox Abdomen smooth and shiny, the hairs being very short 1. Steatoda 

Oj Abdomen hairy. 
&t The paired claws of the legs with a regular series of teeth almost to their 

tip 2. Lathbodectus 

b a These claws with spreading teeth at their base. 

c t Abdomen with a high, pointed hump 3. Abgybodks 

c, Abdomen not with a hump. 

d x Labium and sternum united 4. Spinthabus 

d, Labium not united with the sternum. 

e% Anterior row of eyes curved 5. Thebidula 

e t Anterior row of eyes straight 6. Thebidion 

1. Steatoda Sundevall. Abdomen oval, smooth, and shiny; side 
eyes contiguous; those of the anterior row much larger than the middle 

• See "New England Spiders of the Family Theridiidae/' by J. H. Bmerton, 
Trans. Conn. Acad., Vol. 6, p. 1, 1882. 



pair; the 2 mandibles straight and parallel to each other: the web con- 
sists of a flat net held in place by numerons threads', 4 American species. 

3. borealis (Hentz) (Fig. 661). Body about 6 mm. long and reddish- 
brown in color, the abdomen usually with a light 
stripe running around the front half and one in the 
middle: among stones or in fence corners; common. 

2. Lathrodeotvb W&lckenaer. Abdomen round 
and hairy; side eyes widely separated: 2 American 

L. mactans (Fabricius) (Fig. 662). Body 12 
mm. long and black, with a bright-red, hourglass- 
shaped spot underneath, and one or more red spots 
over the spinnerets and sometimes along the middle 
of the back; abdomen of male ovoid, with a row steaiotfa boream 
of red and white spots in the middle line and 4 (Comet**). 

pairs of red and white stripes on the sides: 
common; web large, with a funnel-shaped retreat 
in tbe middle. 

3. Axqtbodxb Simon. Abdomen with a 
high pointed hump: about 13 American species. 

A. trigonum (Hentz) (Fig. 663). Body yel- 
low, triangular in shape, 3 mm. long and 3 mm. 
high in the female; male with 2 horns in front 
of eyes: common; web between branches or 
leaves, or among the supporting strands of the 
webs of larger spiders. 

4. Sfihtsuvb Hentz. Labium and sternum 
united; abdomen tapering to a blunt point over 
the spinnerets; side eyes close together: 1 
American species. 

8. flavidns Hentz. Body 4 mm. long; 
eep halo thorax circular; upper surface of abdo- 
men flat with a white stripe on each side and 
red and black in the middle: found on low 
plants; web unknown. 

6. Thekiduxa Emerton. Anterior row of 
eyes curved; first legs much longer than the 
fourth: 2 American species. 

T. aphsorula (Hentz). Body 2.5 mm. long; cephalothorax yellow or 
orange with a median black stripe; abdomen round and wider than long, 
and yellowish -gray in color with a greenish-white spot in the middle 
and a black spot at either side: common in bushes. 

Pla. 663— .irtryrodeit 


6. Thehidioh Walekenaer. Anterior row of eyes straight or nearly 
so; the 2 middle pairs of eyes of the same size, and equidistant from 
one another: about 40 American species. 

T. tepidariornm Koch (Fig. 664). Body 6 mm. long, varying in color 
from whitish to black ; cephalothorax usually 
light brown, the dark individuals with 6 
transverse black marks on the abdomen: a 
cosmopolitan species and one of the common- 
est house spiders, being chiefly responsible 
for the webs in the corners; it breeds sev- 
eral times a year and the young and old 
are found at all seasons. 

T. frondram Hentz. Body 3 mm. long, 
and white or bright yellow in color, with 
very variable black markings on the back, 
which may consist of 2 rows of spots or a 
median band: in bushes; common. 

T. diffarena Emerton. Body about 3 

fc'S'yg mm. long; abdomen round, reddish-brown, 

with a red median stripe having white 

Fig. 064— Theridion upida- edges, which is bright in the female and 

1 b, its' web.' ' A ' '' obscure in the male; sternum orange: web on 

low plants, 5 or 6 inches in diameter. 
T. mnrarium Em. Body about 4 mm. long; abdomen round, gray in 
color, with a reddish median stripe, white on the edges; sternum pale, 
with a black edge and a black median stripe : on low bushes. 

Family 8. UNTPH3EDAE. 
Small spiders with an elongate but high abdomen; mandibles with 
teeth around the terminal claw; epigynum and male appendages large and 
complex : web consists of a flat or curved sheet of silk supported above and 
below by great numbers of threads and found either in open woods or near 
the ground in grass and dead leaves, or in caves or cellars. The smaller 
species have the curious babit of flying in the late autumn. They come to 
the tops of fences and other elevated objects and cause their silk to be 
drawn out and floated aloft by the currents of air, until they are themselves 
lifted up and often blown long distances; about 95 American species. 

Key to the genera of Ltnyphiidae here described: 
a, Female with a terminal claw on the pedipalp. 

b, Hinder pair of median eyes not close together 1. T.intpitta 

6, Hinder pair of median eyes close together 2. Lephthtph ANTES 

a, No such terminal claw. 

6, No hard plate on the abdomen 3. Baraom 

B, Abdomen covered by a hard plate 4. Cibatinixla 


1. LOTTO* Latreille. Legs with long spines along their aides; 
maxillae longer than wide; hinder pair of median eyes not near to- 
gether; terminal segment of male pedipalp very large and complex: 
about 22 American species. 

L. MWTgiimta Koch (Fig. 665). 
Body 4 mm. long; cephalothorax long 
and high in front; legs long and slen- 
der; color light yellow with median 
brown markings: web a dome 4 or 5 
inches in diameter hung between plants 
or rocks, in the middle of which the 
spider lives; one of the commonest 
spiders in shady woods. 

L. pbryfft*na Koch. Body 5 mm. 
long; color light yellow with a median 
black stripe which is serrated on both 
margins on the abdomen: web a large 

. _, „„ ■ „__j_ _ j _„„.. Flf. 068 — Web of LinypTUa margi- 

sheet, common in woods and Dear na i n (Emertoo). 


2. IxVBIKI nWRH Meage. Maxillae longer than wide; legs with 
long spines along their sides; hinder pair of median eyes near together; 
sternum heart-shaped; penultimate joint of the legs with a single spine: 
4 American species. 

L. nebolonu (Sundevall) (Fig. 666). Length 4 
mm.; color variable, usually light brownish -ye How with 
gray markings: common in cellars and damp places about 
houses, the web being flat. 

3. Eeiqowe* Savigny and Audouin. Pedipalp 
in the female without a claw; body rather narrow : 
very small spiders which live near the ground in grass, 
dead leaves, etc., in small webs; about 30 American 

E. longvpalpia (Sundevall). Body 2 mm. long, dark 

Lephfhyphan- brown in color; cephalothorax smooth and shiny and 

'(ComstoSo!* sometimes bright orange in color; small pointed teeth 

along the sides of the thorax. 

E. autnnmalis Emerton. Body 1.2 mm. long, of a light color with 

a bright yellow head. 

4. CBKaTOTXLa Emerton. Abdomen covered by a hard plate; 
pedipalp of female without a claw: 21 American species. 

tc„ bj C. B. Crorty. 


0, fluicapt (Cambridge). Body 1.5 mm.; abdomen round, and 
orange in color; head black around the eyes; the head of the male 
extends forwards, forming two humps: very common on small boshes. 

Family 0. EPEIRIDAE.* 
Round-web spiders. Usually large spiders with long legs and an 
abdomen which is rounded or ovoid and often provided with humps; often 
brightly colored; eephalo thorax short, low in front with the eyes near 
the front edge and in 3 transverse 
groups, the 2 lateral pairs being close 
together and separated from the mid- 
dle eyes; 3 terminal claws on each 
foot, usually with accessory spines 
also. The web is round and regular, 
with radiating spokes joined by cross 
threads (Fig. 667). The latter form 
2 spirals, an inner spiral that begins 
in the center and winds outwards, 
covering usually less than a quarter 
of the finished web, and an outer 
spiral that begins at the edge and 
winds inwards, covering a large part 

Fig. 667— An orb web (Emertonl. of the web. The outer spiral is 
1. inner spiral; 2, outer spiral; 3, 
strand going to the neat formed of a sticky thread which holds 

the insects flying against it. The 
spider usually tears down its web and builds a fresh one every night: 
this may be for the purpose of renewing the sticky thread, which gradu- 
ally hardens. About 120 American species are known. 

Key to the genera of Epeiridae here described : 
a, Abdomen not elongate, usually round or ovoid. 
b. Hinder row of eyea strongly carved; large brightly colored spiders. 1. Abotopu 
6, Hinder row of eyes not curved or only slightly so. 
o, Thorax without a deep longitudinal furrow, 
i. Head and thorn* separated by a deep transverse cervical groove. 2. Ctcloba 

d, No distinct cervical groove; thorax usually witb a V-shaped furrow, 
e, Abdomen without spines. 

/, Web entire 3. Efdu 

I, Web lacking n large segment 4. Zilla 

e, Abdomen with prominent spines Fj. Acbosoma 

o, Thorax with a deep longitudinal farrow 6. Manqoba 

a, Body elongate and light-colored. 

b. Groove between the spiracles curved markedly 7. Tetbaqnatoa 

li, This groove nearly straight S. Leucaoob 

* See "New England Spiders of the Family Epeiridae," by J. H. Bmerton, Trans. 
Conn. Acad.. Vol. 6, p. 296, 1864. "American Spiders," etc, by II. McCook, Tot. S, p. 
182, 1803. 


1. Axoiofe Savignv and Audouin. Cepbalothorax flat; bead very 
email; eyes all alike, the second row strongly curved, first row straight 
or curved : about 5 American species. 

A, aurantia Lucas (A. riparia Emertou) (Fig. 668). Body large 
and conspicuous, being often 25 mm. long, with long lege; abdomen 
black and 2 bright yellow or orange bands underneath; cephalothorax 
gray above and yellow underneath : the web is sometimes 2 feet in diam- 
eter and has a zigzag band of silk across the middle; the male has a 
small, irregular web nearby; in grass and bushes; in open fields, especially 
near water. 

A. trifasdata (Forska)) (A. transversa Em.). Like the above, but 
a little smaller; abdomen white or light yellow, crossed by black lines: 
web often in marshes. 

2. Otolou Menge. Head and thorax 
of the female separated by a deep trans- 
verse groove: 5 American species. 

G. conica (Pallas). Abdomen with a 
blunt conical lump at its hinder end; 
length 6 mm.; color gray: the web has a 
band of silk across it in which the spider 

fastens sticks and rubbish, and is pro- V 

tected by its resemblance to them. 

3. Epeiba Walckenaer (Araneus :\ 
Simon). Thorax without a transverse [• 
furrow; the 2 rows of eyes straight or 

nearly so, 4 eyes being median in posi- 
tion and a pair at some distance from 
them on each side: about 57 American 
species. < ; 

E. foliate Koch (E. strix Hentz). 
Length 8 mm.; color brown, with a broad 
scalloped stripe on the back of the abdomen; cepbalotborax with 3 lon- 
gitudinal stripes: common all over the country around houses and on 
bushes and fences. 

E. angulata (Clerek). Length 12 mm.; color dark brown, with a 
yellow stripe on the sternum and yellow spots on the under side of the 
abdomen; anterior end of abdomen with a pair of bumps and a yellow 
spot: common among trees. 

E. cavatica Keyserling (E. cinerea Emerton). Length 18 mm.; color 
dirty white with grayish markings; long white hairs scattered over the 
body; abdomen with 2 small humps in front: common about bouses and 
barns in New England. 


E. globosa Keys. Length 6 mm.; abdomen round and large, and 
yellowish in color, with 4 large, square, whitish or pinkish spots on the 
anterior and 3 or 4 pairs of black spots on the posterior portion: web 
large, with one segment left open or partly open and with a thread 
running from its center to the large nest; common. 

£. prompta Hentz. Body 6 mm. long and gray in color, with vari- 
able black and yellow markings on the back: common in low bushes. 

E. gigas Leach (E. insularis Hentz) (Fig. 669). 
Length 16 mm.; abdomen large and ovoid, and 
bright yellow or orange in color with brown or 
purple markings; cephalothorax dull yellow: in 
bushes and low trees; the spider makes a nest 
of leaves in which it stays, holding a thread which 
runs to the center of the web; in all parts of the 

E. domiciliortim Hentz. Length 8 mm.; color 
Fig. 66ft— Bpeira oigos light yellow with brown markings, sometimes with 

red spots on the abdomen; cephalothorax with 3 
faint stripes; sternum bright yellow in the middle: in bushes and on 

E. trifolittm Hentz. Length 20 mm.; abdomen large and round, 
light or dark brown in color, with white spots; legs with conspicuous 
black or reddish rings; cephalothorax white, with 3 black stripes: in 
bushes and tall weeds; the spider has a nest of leaves joined with the 
center of the web by a thread like E. gigas. 

4. Zxlla Koch. The 2 middle pairs of eyes near the 2 lateral pairs; 
the hinder row of eyes somewhat longer than the 

forward row; abdomen elliptical: about 4 American 

Z. atrica (Koch). Length 7 mm., with a large, 
somewhat flattened abdomen; color gray, with a broad 
scalloped stripe on the abdomen: a segment of the web 
is without cross threads, opposite which a thread runs Aorowma 

from the center of the web to the nest; about houses. (Cometock). 

5. Aoeoboma Perty (Micrathena Sundevall). Small 

brightly colored spiders with a flattened abdomen which is extended 
backwards and furnished with several pairs of pointed projections: the 
web often has a hole in the center; 4 American species. 

A. spinea Hentz (Fig. 670). Length 5 mm.; abdomen narrow in 
front and with 2 long spreading points behind ; 2 pairs of smaller spines 
also present; color white or yellow with black spots; spines red and 


6. Hangoxa Hentz. Thorax elevated behind and with a deep 
median farrow; second row of eyes straight gr curved backwards: 3 
American species. 

M. gibberoaa (Hentz). Bod; 5 mm. long and light yellow or gray 
in color, the abdomen with 2 parallel black lines 
on the hinder half, and a number of small black 
spots: web with about 60 radial spokes and the 
cross spirals very close together. 

7. Tetxaqxatha Latreillo. Slender, light- 
colored spiders living in their webs in the long 
grass in meadows and near water; mandibles 

large, extending forward and divergent: about g 

4 American species. 

T. extensa (L.). Length 6 mm., with abdo- 
men twice as long as the eephalothorax; color 
yellowish-brown or gray. 

8. Lzvoavox White. Elongated spiders with 
the lateral eyes near together and nearly equal in 
size; 3 claws on tbe feet: 2 American species. 

L. hortomm (Hentz) (Fig. 671). Body 6 mm. long; eephalothorax 
and legs bright green; abdomen silvery white above, with a dark line 
through the middle with red and yellow spots: web large, witb a zigzag 
band of silk across the center. 

Family 10. THOMISTTJAE.* 

The erab spiders. Short, flat spiders, usually widened behind, with 
a sidewise gait and a crab-like appearance; the first and second pairs of 
legs much longer than the others and extended at right angles to the 
body; 2 claws on each foot; eyes in two curved rows: about 114 Ameri- 
can species, which are found on walls, flowers, and similar places; they 
do not make a web. 

Key to the genera of Thomisidae here described: 
a. Body and legs crab-like. 
6, Lateral eyes on tubercles, 
c. Two eye tubercles on each side. 

d, Hinder eye tubercle the larger 1. Ticaxua 

d, Front eye tubercle the larger 3. Xtsticos 

e, A single eye tubercle on each side 2. Misdmena 

6, No eye tubercle present. 

o. Labium much longer than wide 4. Philodbomtjs 

c. Labium not longer than wide 5. Bbo 

a, Body long and slender, not crab-like 8. Ttbelltjb 

• See "New England Spiders of tbe Family Tho mini due," by J. B. Bmerton, 
Trans. Conn. Acad., Vol. 8, p. 359, 1892. 



Fig. 672 

Tmarus oaudatua 


1. Txasus Simon. Front of head truncate; hinder row of eyes 

much longer than the forward; lateral eye on each side being raised on 

tubercles, the hinder tubercle on each side being much larger than the 

forward one; abdomen high and pointed behind: 5 American species. 

T. caudatus (Hentz) (Fig. 672). Length 6 mm.; color mottled 

gray; abdomen highest at hinder end, which forms 
a conical knob: on trees and fences; common. 

2. MlflUHENA Latreille. Large, brightly colored 

or white spiders living in flowers, the colors of 

which they often mimic; the 2 lateral eyes on each 

side on a single tubercle : about 20 American species. 

M. vatia Thorell. Length 12 mm.; color white 

or yellow, sometimes with a crimson spot on each 

side of the abdomen and another between the eyes; 

sides of thorax yellowish : common. 

M. asperata (Hentz). Length 6 mm.; color pale yellow or white, 

with dull red markings on the abdomen and a brown stripe on each side 

of the thorax; scattered stiff hairs present; common. 

3. Xystiotjs Koch. Each lateral eye on a tu- 
bercle, the forward one being the larger; median ocular 
area as wide or wider in front than behind : 40 Ameri- 
can species, which live under bark, stones, and leaves. 

X. triguttatus Keyserling. Length 5 mm.; females 
straw-colored or yellow, with black spots on the 
thorax and front of the abdomen and 3 broken trans- 
verse stripes behind; male with a thorax which is dark 
brown at the sides and lighter in the middle, and an 
abdomen banded with black and white: very common 
in grass and low bushes. 

X. versicolor (Keyserling) (Fig. 673). Length 7 
mm.; body flattened, mottled black and gray in color: 
common on trees, fences, etc. 

4. Philodkoxto Walckenaer. Abdomen bluntly 
pointed behind and flat; legs long, the second pair 
being the longest; labium much longer than wide: 24 
American species. 

P. vulgaris (Hentz) (Fig. 674). Length 6 mm.; legs very long, 
spreading an inch or more; color mottled gray with a median marking 
on the abdomen: on fences and walls. 

5. Ebo Keyserling. Labium not longer than wide; second pair of 
legs twice as long as any of the others; median eyes larger than the 
lateral ones; hinder row nearly straight: 3 American species. 

Fig. 67S 

Fig. 674 

Fig. 673— JTw- 
ticus versicolor 

iBmerton). Fig. 
74— Philodro- 
mus vulgaris 



E. latithorax Keys. Length 3 mm.; color gray and white, with 
black spots; body very wide; head narrow in front. 

6. Txbellto Simon. Body long and slender, the legs 
projecting ahead and behind and not sideways; both 
rows of eyes curved: 2 American species. 

T. oblongus (Walckenaer) (T. duttonii Emerton) (Fig. 
675). Length 12 mm.; width 2 mm.; color gray or yellow, 
with dark longitudinal bands and a pair of black spots 
on the hinder part of the abdomen: very common on 
bushes and grass. 

Family 11. CLUBIONTDAE. 

Light-colored spiders usually without color markings; 

upper row of eyes longer and the eyes usually larger 

than the under row; mandibles of females swollen at 

the base : the animals live in flat tubular webs in rolled-up 

Fig. 6To 

leaves or on plants and under bark and stones; about 95 TjheUu* 

American species. (Emerton). 

Key to the genera of Clubionidae here described: 

Ox Posterior spinnerets with a very distinct, conical terminal segment. 
b x Labium much longer than wide and extending beyond the middle of the 

maxillae 1. Clubioka 

b t Labium about as long as wide or less so, and not extending beyond the 
middle of the maxillae ; sternum extending between the hind legs. 

2. Phbubolithxjs 
a, Posterior spinnerets with a very short and fre- 
quently indistinct terminal segment. 
&i Cervical groove present. 

Cx Legs spiny .3. Castiaotctba 

c, Legs not spiny 5. Trachelas 

6 3 Cervical groove absent '. 4. Micaria 

1. Olttbiona Latreille. Hinder legs longer 

than forward; spinnerets distinctly segmented; 

_ labium longer than wide; mandible long; eyes very 

n ** ' near the front margin of head : about 20 American 


0. obesa Hentz (C. crassipalpis Keyserling) 

(Fig. 676). Length 6 mm.; pale in color, without 

markings; mandibles and ends of male pedipalps 

Fig. 676 — oudrtona dark; eyes in each row equidistant, the hinder 
ooe^a (Bmerton). . 

row being the longer: common. 

2. PmtUBOLXTHTO Koch. Each terminal claw with 6 to 10 spatu- 

late hairs; sternum broad and extending between the hind legs: 8 

American species, 


P. alarius (Hentz) (Fig. 677). Length 3 mm.; cephalothoraz light 
yellowish, with a black line on each edge; abdomen covered with irides- 
cent scales which change in color from grayish-green to pink : a very active 
spider living among stones on the ground. 

3. OABTiAjnsrjtA Keyserling. Cervical groove pres- 
ent; anterior median eyes not close to the margin of the 
head; legs spiny: about 18 American species. 

0. descripta (Hentz) (C. crocata Emerton). Length 
8 mm.; body black, with a bright red spot on the end of 
the abdomen; ends of legs yellow: among stones in dry, 
open places; its egg case is a small parchment-like disc 
attached to a rock. 

4. Mzoabza Westring. Body covered with scale-like 
hairs; last segment of the hind spinnerets very short, 
frequently indistinct, with an oblique groove; no cervical 
groove: 13 American species. 

Phrufoiithu* M. aurata (Hentz). Body resembles an ant in size 

(Eme£"). and color; length 6 mm.; color light brown, varying to 

bright yellow and orange: eastern states. 
5. Tsaohklas Koch. Posterior row of eyes curved forward; legs with- 
out or with few spines, dorsal groove present: about 5 American species. 
T. tranquilla Hentz (T. ruber Keyserling). Length 8 mm.; cephalo- 
thoraz wide; abdomen ovoid; color deep orange brown, the abdomen 
much lighter than the cephalothoraz: under stones and leaves. 

Family 12. AGELENTDAE. 

The funnel-web spiders. Cephalothoraz large, and often narrow in 
front and broad behind; cervical groove present; hind spinnerets very 
long and 2- jointed; mandibles large; 3 terminal claws on the feet: mostly 
large spiders which make a flat web on the grass and in the corners in 
barns and cellars, in the middle of which is a funnel-shaped tube form- 
ing the spider's retreat; about 50 American species. 

Key to the genera of Agelenidae here described : 

Oj Spinnerets not in a transverse line. 

&! Both rows of eyes strongly curved backward 1. Aoelbh a 

6, Both rows of eyes not or bat slightly curved backward. 

c, Anterior median eyes much smaller than the lateral 2. Coras 

c, Anterior median eyes either equal in size or smaller than the lateral. 

3. Tbgenabia 
at Spinnerets in a straight or curved line 4. Hahnia 

1. Agxlsha Walckenaer. Both rows of eyes strongly curved back- 
wards so that the anterior median and the posterior lateral are in a 
straight line; terminal segment of the hind spinnerets at least as long 
as the basal segment: about 4 American species. 



Fig. 678 — Agelena 
ncdoia (Emerton) 

A. n»via Walck. Grass spider (Pig. 678). Body 18 mm. long or 
less, and yellowish brown, or black in color, with gray or dark markings 
and spots on the abdomen and broad longitudinal stripes on the cephalo- 
thorax, and covered with fine hairs: the very 
common spider which makes flat webs in the 
grass which are conspicuous when covered by 
dew; also in houses. 

2. Oobas Simon. Rows of eyes not curved 
or but slightly so; anterior median eyes much 
larger than the lateral: 1 species. 

0. medicinalis (Hentz) (Fig. 679). Body 
12 mm. long, light yellowish-brown in color and 
covered with gray hairs; abdomen large and 

oval and marked with gray 
spots of irregular shape: in 
woods among rocks and under 
loose bark, the web is not flat, 
but is usually curved in sev- 
eral places. 

3. Teuhahia Latreille. Eyes all of the same 
size, both rows curved, the forward row but slightly; 
legs long and slender: about 7 American species. 

T. derhami (Scopoli). Body 10 mm. long, pale 
in color, with gray stripes and spots; first and fourth 
pairs of legs the longest: in cellars, barns, etc.; the 
web often forms a thick shelf in the 
corner; very common, having been im- 
ported from Europe, it and Theridion 
tepidariorum making most of the corner 
webs in cellars. 
4. Hahhia Koch. Spinnerets extend across the abdo- 
men in a straight or curved line; anterior middle eyes 
smaller than the lateral : about 6 American species. 

H. agilis Keyserling (27. bimaculata Emerton) (Fig. 
680). Length 3 mm.; cephalothorax bright orange brown 
in color and the legs and abdomen pale yellowish with gray markings: 
common under stones and leaves or among grass and moss. 

Fig. 679 — Coras 

Fig. 680 

Hahnia agilis. 

ventral aspect 


Family 13. PI8AUBIDAE. 

Eyes in 3 rows; cocoon carried in the mandibles of the female; 
cephalothorax broad and flat: ground spiders of large size similar to the 
Lycosidae; about 18 American species. 


1. Pxsatohta Simon. Anterior row with 4 eyes of same size and 
straight; area of the middle eyes longer than broad: 3 American species. 

P. nndata (Walckenaer). Length 13 mm.; color light brownish- 
yellow, with a wide, median, dark band edged with white running 
the length of the body; abdomen long and narrower than the cephalo- 
thorax: common in bushes; no web is made 
until the young are ready to hatch, when 
the female builds a small web about the 
cocoon in which the young may live. 

2. DoLOHEDEfl Latreille. Area of the 
middle eyes as broad or broader than long; anterior 
row of eyes curved forward : 7 American species. 

D. fontanus Emerton (D. tenebrosus Em.) (Fig. 
681). Length 20 mm., with legs spreading 10 cm.; 
color gray; cephalothorax larger than the abdomen 
and with light bands on the side; abdomen with dark 
cross lines: common on the ground in low 
bushes near water with habits like P. 

D. sexpunctatus Hentz. Length 15 

mm.; color dark greenish-gray, with a whitish line 

on each side of the length of the body; abdomen 

larger than the cephalothorax; sternum with 6 dark 

spots : common under stones near the water on which Fig. 681 

... Dolomede* fontanus 

it runs readily. (Emerton). 

Family 14. LYCOSIDAE. # 

Wolf spiders. Large, active spiders which live on or near the 
ground; eyes usually in 3 rows; in the front row are 4 small eyes and 
back of these 2 pairs of large eyes; cephalothorax high and prismatic; 
feet with 3 claws, the small one surrounded by hairs : no web built, but 
many species line their retreats with silk; the cocoon is attached to the 
spinnerets and the young spiders are carried for a short time on the 
mother's back; about 114 American species. 

Key to the genera of Lycosidae here described : 

o, Labium longer than broad. 
5* Posterior spinnerets not longer than the anterior or but slightly so. 

0i Cephalothorax highest in the cephalic region 1. Lycosa 

c, Cephalothorax highest in the middle 2. Tbochosa 

b, Posterior spinnerets half again as long as the anterior 4. Pirata 

c, Labium at least as broad as long 3. Pardosa 

• See "New England Lycosidae/' by J. H. Emerton, Trans. Conn. Acad., Vol. 6, p. 
481, 1885. "Canadian Spiders/' by same, ibid., Vol. 9, 1895. "Descriptions of North 
American Araneae of the Families Lycosidae and Pisauridae/' by T. H. Montgomery, 
Proc. Acad. Nat 8ci., Phila., 1904, p. 261. 


1. Lycosa Latreille. Head very high and with sloping sides; 
labium longer than broad; hinder 2 pairs of eyes not on the margin 
of the head ; legs usually long and with long spines : about 50 American 

L. helluo Walckenaer (L. nidicola Emerton). Length 18 mm.; long- 
est legs 25 mm.; color dull yellow or greenish-brown, with 3 narrow 
yellow stripes on the cephalothoraz and a pointed stripe on the front 
half of the abdomen : common under stones in moist meadows and woods ; 
the female is seen with her cocoon in early summer. 

L. avida Walck. (L. communis Em.) (Fig. 682). Length 10 mm.; 
longest legs 18 mm. ; color from gray to black, with 3 light stripes on the 
cephalothoraz and a pair of broad median stripes meeting behind on the 

abdomen : common in pastures, the female is carry- 
ing her cocoon in early summer. 

L. rabida Walck. (L. scutulata Hentz). Length 
13 mm.; longest legs 26 mm.; cephalothoraz dark 
gray in color, with 3 light stripes; abdomen with a 
wide median stripe and several light and dark lines 
at each side. 

L. carolinensis Walck. One of our largest 

spiders, sometimes over 35 mm. long with legs 

f spreading 75 mm. ; body covered with thick hair and 

/brown above and black beneath in color: on the 
ground or in its hole, a deep cylindrical pit, in which 
the eggs are hidden. 

£&•%£&£ K »*«* **" < L - ^enicola Seudder). Sand 

spiders. Length 18 mm. ; color of male gray or sand 
color, with a spot in the middle of the abdomen, female gray or slate 
color, with a broad, serrate band on the abdomen: the female lives in 
a hole 10 inches deep, around the mouth of which is sometimes a low 
turret of sticks. 

2. Tboohoba Koch. Legs quite short; first row of eyes about as 
long as the second, which is not quite as long as the third row: 4 
American species. 

T. cinerea (Fabricius). Length 12 mm.; body gray or sand color 
with small spots : common on beaches and in sandy fields. 

3. Pakdoba Koch. Slender spiders with long legs; labium at least 
as broad as long; front row of eyes shorter than the second; second and 
third pair of eyes large and near the lateral margin of the head: 30 
American species. 

P. nigropalpis Emerton. Length 6 mm.; color black with a wide, 
irregular median area; pedipalps of male black: on the ground. 



bUU , 

Fig. 683 — Pirata 
piratic a (Emerton). 
A, dorsal aspect; B, 
front view, showing 
the eyes. 

4. Pibata Sundevall. Labium longer than broad ; first row of eyes 

as broad as the second: beneath stones and in the grass near the water 

over the surface of which they may freely run; 16 American species. 

P. piratica (Clerck) (P. marxi Stone) (Fig. 683). Length 6 mm.; 

color pale yellow with gray or black markings; 

eyes of the second row about half their diameter 


Family 15. ATTIDAE. # 

dlffipy* ^9fr Jumping spiders. Eyes in 3 rows, the front 

row usually curved and composed of 4 large eyes, 
the second row of 2 very small eyes, the third row 
far back on the head and composed of 2 large eyes 
which are usually turned a little backward; cepha- 
lothorax large and wide in front; legs strong and 
short and with 2 terminal claws on each; body cov- 
ered with hairs or scales: no web made, but some 
species make silk bag-like retreats on plants and 

under stones; the spiders run and jump sidewards and backwards as well 

as forwards; about 213 American species. 

Key to the genera of Attidae here described : 

a, Body not shaped like an ant. 
bx Abdomen not longer than the hind legs, 
c, Body not noticeably flattened. 
d\ Front row of eyes not touching one another. 

e x Eye area broader than long, body short and wide 1. Attus 

e. Eye area not broader than long. 

fi Eye area somewhat wider behind than in front 2. Phidippus 

/, Eye area quadrangular 3. Dendbtfhantes 

d, Eyes of front row touch one another 4. Salticus 

o, Body noticeably flattened 5. Mabpissa 

Oj Abdomen longer than hind legs .6. Hyctia 

c, Body like an ant in shape 7. Synemosyna 

1. Attus Walckenaer. Eye area broader than long; 
first leg with 2 rows of spines on distal half; third leg 
shorter than the fourth: about 6 American species. 

A. palustris Peckham (Fig. 684). Length 6 mm.; 
color brown or gray, with a median white line on the 
cephalothorax; abdomen with white spots and markings: 
on plants, with nests among the leaves. 

2. Phidippus Koch. Cephalothorax high; eye area wider behind 
than in front; first leg thick and long; third leg shorter than the fourth: 
about 50 American species. 

• See "Attidae of North America/' by G. W. and B. G. Peckham, Trans. Wit. 
Acad. Sci., Vol. 7, 1888. "New England Spiders of the Family Attidae/' by J. H. 
Bmerton, Trans. Conn. Acad., Vol. 6, p. 220, 1891. 

Fig. 684— At- 
tus palustris 


P. podagrosns Hentz (P. multiformis Emerton) (Fig. 885). Length 
8 mm.; males black, with white and orange markings on the abdomen; 
female brown, mixed with black, white, and yellow, 
there being 3 or 4 pairs of white spots on the abdo- 
men of both sexes: very common on plants, with bag- 
like nests among the leaves. 

P. andaz Hentz. Length 12 mm.; color black, 
with 3 large, white spots on the abdomen and several 
smaller ones: common under stones and sticks where 
it has a nest. 

3. DBaD&YFHUrrxs Koch. Second and third 

rows of eyes both small; eye area forms a quadrangle; 

cephalothorax rather high and short; 

third leg shorter than fourth: about 

22 American species. Pis- eau—PMdip- 

D. capitatns (Hentz) (D. (estiva- ""faKerttD). 
Its Peckbam). Length 5 mm.; legs 
ringed; color variable, in male dark brown with a white 
stripe on each side, in female light yellow with 4 pairs 
of brown spots on the abdomen: common on bushes. 

4. SaLTtmra Latreille (Epibtamum 
Hentz). Eyes of front row touching one 

n ggg 8aitt ^ another ; mandibles of male very long and 

?!toerto™* projecting in front of head: 4 American 
8. scenicns (Clerck) (Fig. 686). Length 6 mm.; gray 
in color with 2 pairs of oblique, white spots on the abdo- 
men and 2 white spots on the cephalothorax; one of 
the commonest jumping spiders, on bouses and fences; 
also in Europe. 

5. H&SFIB8A. Koch (Marptusa Thorell). Cephalo- 
thorax and abdomen both widened in the middle and of 
about the same size; legs long and thick: 6 American 

M. familiaria (Hentz). Length 12 mm.; body flat- 
tened, gray in color; cephalothorax with a dark brown 
band along each side; abdomen with a broad, irregular, 
yellowish- white median band : common on houses and „. „_ 

6. Htctia Simon. Abdomen long and slender and 

narrower than the cephalothorax ; front legs much larger than the others : 
2 American species. 


H. pikei Peckham (Fig. 6S7). Body 8 mm. long and very slender, 
with the abdomen twice as long as the cephalothorax and longer than the 
hind legs; abdomen with a very broad, black stripe having 3 notches on 
each side; rest of the body whitish; front legs brown, others white: 
common on sand and grass, on which it often lies with the legs parallel 
to the body, so that it would be seen with difficulty. 

7. Stvekostha Hentz. Cephalothorax and abdomen each with a 
deep dorsal depression; middle of the body Blender, front middle eyes 
large, the rest small; 1 species. 

S. formica Hentz. Ant-like spider (Fig. 688). Body 6 mm. long 

and very slender; cephalothorax narrowed behind and the abdomen in 

front, and each has a deep dorsal depression in the middle ; 

color black with yellowish markings: the spider resembles 

an ant in shape and method of walking. 

Order 8. A0AS3SA.* 

The mites. Small arachnids, in which cephalothorax 
and abdomen are unsegmented and so joined that the short, 
thick body is more or less ovoid or globose in shape. In 
some forms a suture separates the forward part of the body 
with two pairs of legs from the hinder part with the two 
hinder pairs; in a few also the abdomen is elongated and 
annuls ted, although not segmented. The six pairs of ap- 
sj^iemolitfNo peudages are well developed and consist of the mandibles 
(ljf,n™toa). and pedipalps and four pairs of legs, except in the Brio- 
phyidae, which have but two pairs. The mandibles may be 
chelate or formed for piercing and sucking. The pedipalps are usually 
more or less leg-like, with five joints or less, and in some forms they 
are chelate or subchelate; the basal joints may form plates called 
the maxillae, or they may unite to form a lip or labium. Accessory 
mouth parts are often present, as a hypostome or under lip and tongue, 
and an upper lip or epistome; the latter may be united with the 
lip below to form a tube called the rostrum, from which the man- 
dibles protrude. The legs are usually 5-jointed and end each with two 
claws. The external surface of the body is more or Jess covered with 
tactile hairs or with scales. Eyes are either present or absent. The 

• See "A Treatise on the A carina or Mites," by Nathan Backs, Proc. TJ. 8. Nat 
Him, Vol. 28. p. 1, 1B0G. "A Catalogue of the Ami-Inn or Mites of the United 
States," by Nathan 1'ltnks, same. Vol. 32, p. 695, 1B0T. "The Life History and 
Blnomlcs of Some North American TlekB." by W. A. Hooker and others, Bull. 106. 
Bar. Ent. V. 8. DcpL Ag., 11)12. "New Mites." by II. E. Swing, Bull. Am, Has. 

Nat. Hint., ToL 32, p. S3, 1913. "Tbe Acarlna," by N. Banks, Bep. 106, Bar. Ent., 


anus is at the hinder end of the body; the genital pore lies in front 
of it. 

The internal structure is characterized by its compactness. The 
digestive tract is well developed. Two Malpighian tubules, if any, are 
present. Many forms have no special respiratory system; others have 
tracheae, which open to the outside through a pair of spiracles situated 
either at the base of the mandibles or near the hind legs. 

The nerve ganglia are all united into a single mass, which is pierced 
by the <Bsophagus. Mites are unisexual animals. The young animal is 
usually born as a larva with six legs (Fig. 713, C) ; after feeding awhile 
it passes into a resting stage, from which it emerges as a so-called 
nymph, which has eight legs but no genital orifice; at the end of the 
nymphal stage it again becomes quiescent and develops into the adult. 
In some forms the development is abbreviated and the young animal is 
born as a nymph, or even as an adult. The six-legged larval stage has 
been observed in certain species to be preceded by an eight-legged embry- 
onic stage, which seems to indicate that the former condition is not a 
primitive one. 

Most mites are land animals and about half the species are parasitic, 
many, as the itch and mange mites and the ticks, being among the most 
troublesome and even dangerous parasites infecting man and his domestic 
animals. Many are parasitic on insects, especially on beetles and ants. 
A few are entoparasites, Halarachne, living in the trachea of seals, and 
Pneumonyssua, in the lungs of a monkey. The non-parasitic forms eat 
small animals, including each other, and also decaying plant or animal 
matter, and are found on plants and the ground, under bark or dead 
leaves, while some form galls on plants. The Hydrachnidoe and Halaca- 
ridae are aquatic, the former living in fresh and the latter in salt water. 
They are, however, very little modified for swimming, and possess no gills. 
The order contains about 3,000 species, about 500 being known in this 
country. These are grouped in about 26 families. 

Key to the families of Acarina here described : 

Ox Body elongate and worm-like, the hinder part ringed ; animals minnte. 

&! Gall mites ; but 4 legs present 1. Eriophyidae 

&, Eight legs present ; mammalian parasites 2. Demodicidab 

a% Body not worm-like. 
\ No spiracles or trachea present ; minute mites. 
Ct On mammals or birds, 
dj Itch and mange mites ; parasites in the skin of mammals. .3. Sabcoptidab 

d a Bird mites ; among the feathers of birds 4. Analoesidae 

o, In fruit, grain, cheese, etc., and in certain plants 5. Tyboglyphidae 

6, Spiracles and tracheae usually present. 
Cx Horny mites ; a pair of usually club-shaped bristles on cephalothoraz. 

6. Oribattdab 
c a No such bristles. 



d, Each spiracle in a stigmal plate (Fig. 700, C) near the fourth pair of leg*. 
e x . Stigmal plate in front of fourth leg. 

fx Not on birds (except the genus Dermanyssus) 7. Gamasidak 

/, Parasitic on birds 8. Abgasidae 

e, Stigmal plate behind fourth leg 9. Ixodedae 

da Spiracles not in stigmal plates, but at the base of the mandibles or near 
the fourth pair of legs. 
Cx Aquatic mites. 

f x Fresh-water mites 10. Htdrachnidae 

U Salt-water mites 11. Halacabidae 

e, Not aquatic 

f x Mandibles long and snout-like 12. Bdbludab 

/, Mandibles not so ; body often red. 

ff x Mandibles chelate ; eyes stalked 13. Tbombidiidae 

ft Mandibles piercing ; eyes sessile. 
hx Mid-dorsal line present; not web-spinning. . . .14. Rhtncholophidae 
hi No mid-dorsal line ; web-spinning 15. Tetranychidae 

— j. 

Family 1. ERIOPHYIDAE.* (Phytoptidae.) 

Gall mites. Body minute and worm-like, the hinder 
part being greatly prolonged and ringed ; eyes and tracheae 
absent ; but 2 pairs of legs present, the hinder 2 parts being 
represented by wart-like projections or by hairs ; pedipalps 
leg-like and 3-jointed, and holding between them the ros- 
trum, in which lie the needle-like mandibles; anus at the 
hinder end. The animals feed on plant juices and are the 
cause of galls, fuzzy spots, and other deformed structures 
on plants. The gall always has an opening (differing in 
this respect from those of the Eymenoptera and the Dip- 
tera, but not the Homoptera) and vary much in form 
among the different species. A fuzzy spot or erineum is a 
dense .mass of twisted hairs, among which the mites live. 
Some of these mites live in buds and kill them, others cause 
the edge or surface of a leaf to curl or fold, while still 
others produce abnormal growths on twigs. The family 
contains about 227 species, 27 species being American. 

E&IOPHYES von Siebold (Phytoptus Dujardin). 
Number of rings about the same on upper and under sides 
of the body: about 144 species, 22 American. 
E. pyri (Pagenstecker). Pear-leaf blister. Length .19 mm.; width 

.05 mm.: causes round, red spots on pear leaves, the opening being on 

the under side; the animals winter in the leaf buds. 

• See "The Phytoptl and Other Injurious Plant Mites," by H. Carman, Twelfth 
Rep. of St Ent Illinois, 1883, p. 23. "Eriophyldae," by A. Nalepa, Das Tlerrefch, 
1898. "Galls and Insects Producing Them/' by M. S. Cook, Ohio Nat, Vol. 2, p. 263 ; 
Vol. 8, p. 419 ; and Vol 4, p. 125, 1902-04. "The Briophyidae, Part I, The Apple and 
Pear Mites," by P. J. Parrott, H. B. Hodgklns and W. J. Schoener, Bull. 283, N. T. 
Ag. Ex. St, 1906. 

Fig. 689 


tlic under 
the upper aide; length 


E. vitis (Landois) (Fig. 689). Produces 
side of grape leaves, winch causes a swelling 
.16 mm.; width .032 mm. 

E. qnadrlpos (Shimer). Produces round galls on 
leaves of the soft maple. 

Body minute and worm-like, the hinder part being 
greatly prolonged and ringed; eyes and tracheae absent; 

4 pairs of 3-jointed legs; pedipalps close against the ros- 
trum; anus just back of the hind legs: 1 genus with about 

5 species. 

Dexosex Owen. With the characters given above: 
several species, which live in sebaceous glands and hair 
follicles of man and the domestic animals. 

D. folUcnlornm Simon (Fig. 690). Length .4 mm. or less; width 
.05 mm.: in the skin of the human face, supposed to be the cause of 
"blackheads"; also in cattle and hogs. 

D. bovis Stiles. Length 25 mm.; width .064 mm.: in the skin of 
cattle, canning swellings of the size of a pea in the hide. 

Family 3. BABCOPTIDAE." 
Itch mites. Body minute, globular, or ovoid in shape, finely striated 
on the surface and with a few long bristles; eyes and tracheae absent; 
legs short, each ending in 1 or 2 claws or a stalked or sessile sucker or a 

bristle; pedipalps close against the rostrum; mandibles usually chelate: 
in the skin of mammals and a few birds, causing itch and mange. The 
female burrows through the skin, feeding on the tissues, and leaving a 
row of eggs behind her, and finally dies at the end of her burrow. The 

* See "Demodlddae et SarcopHda 

" Da« Tlerrelcb, 1869. 



Fig. 692 
female (Banks). 

Pioroptes ovi 


young female on being fertilized starts a burrow and thus a host 
becomes infested in patches. About 100 species, 13 species being 

1. Sabooptzs Latreille. The first two pairs of legs end with 
stalked suckers and in the male the fourth pair also; the others end 

each with a long bristle ; mandibles chelate : in mammals, 
burrowing in the skin; about 14 species, 6 American. 
S. scabiei (DeGeer) (8. hominis Hering). Itch mite 
(Fig. 691). Length of female .45 mm.; width .35 mm.; 
male half as large; egg .14 mm. long: causes itch in 
man and mange in hogs. 

S. cauls Gerlach. Mange mite. Length of female 
.48 ma; width .35 mm.; egg .17 mm. long: causes 
mange in dogs, also in man* 

S. cati Hering. Mange mite. Length of female 
.25 mm.; width .2 mm.; egg .1 mm. long: causes mange 
in cats. 

2. PS0B0PTE8 Gervais. Mandibles adapted for 
piercing and not burrowing; stalks of leg suckers jointed: on the 
surface of the skin of mammals, where they suck blood; 5 species. 

P. ovis Hering. Scab mite (Fig. 692). Length of 
female .60 mm.; width .40 mm.; egg .2 mm. long: on 
sheep, cattle, and horses, causing scab; the eggs hatch 
in 2 or 3 days and the young mature in 15 days; the 
females live several weeks, laying numerous eggs; an 
infection thus spreads very rapidly and may cause the 
death of the host; common in the west. 

3. Ohobiopteb Gervais. Females with suckers on 
the fourth pair of legs: on the surface of the skin of 
mammals, being restricted to certain parts of the 
animal; 2 species. 

0. communis Ziirn. Length of female .42 mm.; width .27 mm.: 
causes local inflammation in the ears of dogs, cats, and rabbits. 

4. 0HEXID000PTS8 Fiirst. Female without suckers on any of the 
legs; mandibles chelate: on birds; 2 American species. 

0. mutans Robin (Fig. 693). Length of female .45 mm.; width .35 
mm. : the itch mite of fowls, causing scaly leg, but also appearing among 
the feathers. 

Fig. 693 


Family 4. ANALGESIDAE. (Dsbmaliichidaz.) 

Bird mites. Minute mites with an elongated body, a transversely 
striated integument and often a transverse suture between the front 2 


and the back 2 pairs of legs; mandibles usually chelate and beneath an 
epistome; legs with 5 joints and with a terminal sucker; in some genera 
the male has a pair of clasping suckers and copulatory legs; abdomen 
often bilobed behind: 31 genera and 400 species, which live upon birds, 
feeding on the feathers, epidermal scales, etc., and usually not parasites; 
24 American species. 

1. Ajtaloeb Nitzsch (Dermaleichus Koch). Body elongate, with the 
hinder end rounded or pointed, and 

never deeply bilobed; spines on the 
first pair of legs; third pair of legs 
of male larger than the others and 
ending with claws and not suckers; 
basal joint of first and second leg with 
a backward projection: on singing 
birds; 23 species, American. 

A. panerinns (L.) (Fig. 694). 
Length .45 mm.; third pair of legs of 
male enormously enlarged and used as 
clampers; a European mite, found on 
several species of American birds. a, male" Bjjemalfc 

2. MEomifiA Berlese. Third pair 

of legs much larger than the fourth, with long spines on the terminal 
joint; end of abdomen deeply bilobed in male: 42 species, fi American. 
M. colnmbM Bnchholz. Length .33 mm. | each abdominal lobe in 
male with 2 long and several small bristles; space between the lobes 
filled in by a membrane; on domestic pigeons and other birds. 


Minute mites with an elongated body and a smooth integument; legs 
alike in the two sexes; mandibles usually chelate; eyes and tracheae 
absent; pedipalps close against the mouth parts; young bom with 3 
pairs of legs, in most forms passing through a stage called the hypopus, 
in which it has 8 legs, but no mouth and no distinct mouth parts, but 
with suckers on the under surface, which enable it to attach itself to 
some insect or other animal which will transport it to some new local- 
ity, where it completes its metamorphosis: abont 47 species, 27 species 
being American; they are not parasitic, but live on dried or decaying 
animal and plant substances, but are often a pest to housekeepers, gar- 
deners, and grocers, especially as the hypopus is often spread by 
house flies. 

" bj N. Banks, Tech. 


1. Tyboglyphub Latreille. Body elliptical, with a suture between 
the second and third pairs of legs; male with 2 suckers on each side of 

the genital pore; mandibles chelate; a sucker at the 
top of each foot: about 8 species. 

T. giro (L.). Cheese mite. Length .6 mm; 
width .3 mm.; color whitish: in old cheese and sim- 
ilar substances. 

/ ^ ]^ T * farinae (DeGeer) (Fig. 695). Length of 

v ~ male .5 mm. ; of female .3 mm. ; color whitish : in flour, 

grain, and stored foods; cosmopolitan; often a pest. 
T. linterni Osborn. Similar to the above, but 
viz 695 smaller and with very long bristles extending back- 

Tyroglyghua farinae wards from the body: in mushrooms. 

2. Rhizoolyphttb Claparede. Suture between 
the second and third pair of legs; mandibles chelate; male with ventral 
suckers; feet short, with stout claws and spines: 2 species. 

R. hyacinth! (Boisduval). Bulb mite. Length .75 mm.: burrows 
into the bulbs of cultivated plants, giving entrance to fungi and bac- 
teria; often a pest in hot and green houses. 

Family 6. ORIBATIDAE.* 

Horny or beetle mites. Body minute and divided into 2 parts by a 
transverse suture; integument hard, with few hairs; a bristle, which is 
often long, prominent, and club-shaped, and is called the pseudostig- 
matic organ, arises from a depression near the hinder margin of the 
cephalothorax on each side (Fig. 696,1); mouth parts and pedipalps 
small and hidden beneath the head; mandibles chelate; claws 1 or 3; 
the young are often very bizarre in shape: about 20 genera with over 
300 species, which feed principally on vegetable or decaying animal mat- 
ter and are not parasitic, but live in moss, grass, among decaying leaves, 
in crevices of bark, etc. 

Key to the genera of Oribatidae here described : 

Ox Abdomen with a pair of wins-like expansions 1. Galumna 

a, No such expansions. 
b x Cephalothorax with a pair of dorsolateral ridges. 

Ct Body smooth 2. Liacabus 

c, Body rough ; cephalothorax and abdomen not distinctly separated. 


6, No such ridges ; 3 claws on each leg. 

dy Body flat, often rectangular 4. Nothbus 

d\ Abdomen very high with concentric rings 5. Neoltodes 

* See "On the Orihatoidea of the United States," by N. Banks, Trans. Am. Ent 
8oc. f Vol. 22, p. 1, 1S95. "Oribatidae/' by A. D. Michael, Das Tlerreich, 1898. "New 
Oribatidae from the United States/' by N. Banks, Proc. Acad. Nat. Scl., Phlla., 1900. 
p. 490. 



Pig. 696 — Llaoarua ntUdu* 
(Banks) ; pseudoatigmatic organ. 

1. Oaluxha Heyden (Oribata Michael). Body shining black or 
brown in color, with a pair of horizontal wing-like expansions at the side 
of the abdomen and with 3 claws on each foot: 21 American species; in 
moss or on trees. 

Gk pratensis Banks. Length .7 mm.; yellowish-brown in color: often 
common in meadows. 

Gh emarginata Banks. Body dark 
reddish-brown in color and .9 mm. long; 
wing emarginate below: often common 
in moss, or on the ground. 

2. Liaoajius Michael. Body smooth, 
last 3 pairs of legs inserted under the 
body, each ending with 3 claws : 9 Amer- 
ican species. 

L. nitidus Banks (Fig. 696). Body 1 mm. long, subspherical, shining 
dark reddish-brown or black: under fallen leaves, stones, etc.; common. 

3. Soutovebtex Michael. Divisions between cephalothorax and 
abdomen not very distinct; body rough and sculptured: 2 American 

S. marinus Banks. Paired bristles on cephalothorax wanting: on 
the rocks between tide marks on the Atlantic seashore. 

4. Noth&us Koch. Body rough and more or 
less rectangular; back flat or concave; legs short, 
thick, and rough, ending with 3 claws: 20 species, 
which live in moss, on bark of trees, or on rocks, 7 

N. exdsus Banks. Length .7 mm. ; most of the 
hairs serrated: on the bark of spruce trees; New 
York state. 

N. rugulosus Banks. Body dark brown and 
very rough, appearing like a piece of dirt: common 
under loose bark. 
5. Nsoliodes Berlese. Abdomen convex and very high, with con- 
centric rings; feet with 3 claws: 3 species. 

N. concentric* (Say) (Fig. 697). Body black, 1.5 mm. long; color 
brown: on bark of trees; Europe. 

Pig. 697 — Neoliodes 



Family 7/ GAMASIDAE. 

Scavenger mites. Body broad, with short legs; eyes absent; man- 
dibles usually chelate, and beneath them is a bifid hypostome; pedipalps 
5-jointed and prominent; legs 6- jointed and ending with 2 claws or with 
a sucker; tracheae present, a pair of spiracles being located above the 



fourth legs, each being surrounded by a chitinous ring called the stig- 
ma! plate or peritreme, which usually extends forwards a long distance; 
the young mostly born with 3 pairs of legs : numerous species and about 
18 American genera, some of the species being parasitic on insects, espe- 
cially beetles, and on vertebrates, while many species use insects for 
transportation; some lead a free life in moss and on the ground. 
Key to the genera of Gamasidae here described: 

&x Free-living or attached to insects and rarely to vertebrates. 
&, First pair of legs inserted on one side of the month opening. 

Ci Leg with one claw ; female genital plate triangular 1. Gamasus 

c, Leg 1 without claws ; leg 2 thickened 2. Macbocheles 

&, First pair of legs inserted in the same opening as the mouth parts. 

4. Ubofoda 
a. Parasitic on birds 3. Debmanyssus 

1. Gakasus Latreille. Body usually flattened, with or without a 
transverse dorsal suture; female genital plate triangular; male genital 
pore on anterior margin of sternal plate: about 10 American species, 
which live on the ground, among fallen leaves, etc., or on insects. 

G. coleoptorum (L.). Length .6 mm.; transverse dorsal suture pres- 
ent; 4 large spines projecting from the hinder end; anterior end trian- 
gular; first pair of legs with sucking discs: on beetles. 

2. Macbocheles Latreille. Body elongate, with 
no transverse dorsal suture; second leg enlarged, in 
male curved and armed with teeth; mandibles very 
thick; male genital pore on anterior margin of 
sternal plate; first pair of legs without claws: 
several species. 

M. mcostua Banks. Body reddish-brown and 1 
mm. long, with 8 rows of clavate hairs above and a 
few on the hinder margin: common in ants' nests. 

3. Dekkajtysbits Duges. Bird mites. Body 
elongate and not distinctly constricted; hind legs 
not reaching the hinder end; mandibles chelate in 
male, long and piercing in female : parasitic on birds, 
especially domesticated ones; 1 American species. 

D. gallinae (DeGeer). Chicken mite (Fig. 698). Body .7 mm. 
long, .4 mm. wide, pear-shaped and flat and reddish in color: the mites hide 
during the day in the coop and at night attack the fowls and suck their 
blood, and are often a serious pest; they frequently attack dogs, eats, 
and horses, as well as man. 

4. TJbopoda Latreille. Body ovoid, with depressions on the under 
side for the reception of the legs; mandibles very long and slender, and 
chelate: on beetles, ants, and other insects; some are parasitic, but most 

Fig. 698 — Dermanys- 

9U9 gallinae 



of the species use the insects only for transportation, being young ani- 
mals in the nymphal stage which attach themselves by a pedicel of 
excrement: as adults they live on the ground among fallen leaves, and 
in similar places; several species. 

6. U. vogitans (DeQeer) (Fig. 699). Body 
arched, smooth, brownish in color, about 1 mm. 

Family 8. ABGA8IDAE. 

Ticks. No scutum, as in the Ixodidae; stigmal 
plate between legs 3 and 4: lfi American species, ^StutaSSS;* 

which are nocturnal parasites of domestic birds. 

Akoab Latreille. With the characters of thB family: about 10 

A. porsicus Fischer {A, miniatus Koch). The Miana bug. Body 
oval in shape, 5 mm. long in the male and 10 mm. in the female and 
brown in color: often a dangerous parasite of chickens from Florida to 
California; cosmopolitan; in western Asia it bites persons and is mnch 

Family ». IXODIDAE.* 

Ticks. Body often large, and covered with a leathery integument 
capable of great distention in the female, with prominent, slender legs 
and beak-like mouth parts; anterior dorsal surface covered with a horny 
shield, the scutum (Fig. 700, B), which in the male extends over the 
entire back; articulating with the anterior margin of this is the head or 
capitnlum, on which in the female are 2 pitted spots; head bears the 
short, thick, 3 or 4-jointed pedipalps at the sides and in the middle, 
the elongated beak or rostrum, which is made up of the 2 mandibular 
sheaths above, and the toothed hypostome or under lip beneath, with 
the 2 mandibles between, the latter organs being toothed at the tip; 
eyes present or not; tracheae present, the spiracles being just behind 
the last pair of legs, each surrounded by a stigmal plate or peritreme 
(Fig. 700, C); legs 6- jointed, ending with 2 claws and a pad, the foot 
of first pair also bearing a sense organ called Haller's organ: parasitic 
on mammals, birds, and reptiles; the female, when gorged with blood, 
falls to the ground to lay her eggs; the young ticks, which have but 
6 legs at first, usually ascend some plant and are brushed off by a 
passing vertebrate which can set as a host; 250 species, about 35 

• See "The Cattle Tie** of tbe United States," by D. C. Salmon and C. W. Stllea, 
Rep. Bureau of An. Inu., U. S. DepL Of As., 1802, p. 380. "Iiodldae," by L. O. 
Nenman, Dai Tlerrelch, 1911. 


Key to the genera of Ixodidae here described: 

a\ Pedipalps much longer than broad. 

b x Eyes absent 1- Ixodes 

6, Eyes present 2. Amblyomma 

a, Pedipalps very short and thick. 

&! Stigmal plate round 3. Maboaropus 

b t Stigmal plate comma-shaped 4. Debmacentob 

1. Ixodes Latreille. Eyes absent; pedipalps and beak long and of 
the same length; anal groove surrounds anus anteriorly and is open pos- 
teriorly: over 50 species, about 14 in America. 

L ricinus (L.). The castor bean tick. Body oval, in male 3.5 mm. 
long and 2 mm. broad and high ; in female 4 mm. to 11 mm. long, accord- 
ing to the amount of blood it has sucked, and brown or yellow in color; 

at the base of the 
first pair of legs in 

- • jUJju— the female is a 

strong median 

spine: cosmopoli- 

C^HSl tan; often common 
Sk, J 3 \mJ ^* on domestic ani- 

A X ^ ^/ mals, rabbits, etc., 

Fig. 700— Amblyomma americanum (Hooker). A, dorsal *ko on man. 
aspect of female; B, the scutum; C, stigmal plate. 1, t j.~_««.i-..i- 

first leg; 2, pedipalps; 3, rostrum. *• SCapillarU 

Say. Body 3 to 6 
mm. long and 2 mm. broad, with a dark brown shield: common in the 
southern states on all kinds of wild animals, dogs, and cattle. 

2. Axblyokka Koch. Eyes present; anal groove surrounds anus 
posteriorly and is open anteriorly; pedipalps and beak long: 86 species, 
4 American. 

A. americanum (L.). Lone star tick (Fig. 700). Body 4 mm. long, 
3 mm. wide; the gravid female may measure 12 mm. in length and 8 
mm. breadth; color of male brown, of female bluish, with a brown 
scutum, the hinder end of which has a conspicuous yellowish spot, 
which gives the animal its popular name: often common on cattle, also 
on man. 

3. Marqaboptts Karsch (Boophilus Curtice). Eyes present, often 
indistinct; pedipalps short and broad, with the second and third joints 
extended laterally into sharp points; spiracles round: 2 species, 1 

M. annulatue* (Say) (M. bovis Riley). Texas cattle tick (Fig. 701). 
Body oval and 2.30 mm. long, and brown in color in male, and elliptical 

* Sec "Texas Fever/' etc., by J. R. Mofaler. Bull. 78, Bur. Animal Industry, 
Dept. Ag. 1905. 



or more or less rectangular and up to 13 mm. long and yellowish or 
slate-color in the female : southern states, on cattle, often very common, 
causing the destructive Texas fever, the disease being caused by the 
inoculation of the cattle by the tick of Babesia bigemina, a sporozoan 
blood parasite (see page 47). 

4. Desmaoevtob Koch. Eyes present; pedipalps short and broad; 
stigmal plate comma-shaped; scutum partially white or yellow: 20 
species, about 4 American. 

D. variabilis (Say) (D. electus Koch). Dog tick (Fig. 702). Body 
oval or rectangular; scutum reddish-brown with white spots; stigmal 

Fig. 701 

Fig. 702 

Jig. 701 — Margaropus annulatus (Banks). A, female; B, male. Fig. 702 — Derma- 

centor variabilis — male (Banks). 

plate finely punctate; color brown, variegated; length of replete female 
15 mm.; breadth 9 mm.: on domestic animals and man, often abundant 
in the eastern and central states, being the tick that often attaches to 
persons in the woods. 

D. venustua* Banks. The Rocky Mountain spotted-fever tick. Body 
an elongated oval and 2 to 6 mm. long in the male and about 15 mm. 
long in the female and reddish-brown in color: the northwestern states; 
the larvae live on small mammals and the adults on the larger domestic 
animals and man ; the cause of a very dangerous fever which is the result 
of the inoculation by the tick of a sporozoan blood parasite, Babesia 
hominis (see page 47). 

Family 10. HYDRACHNIDAE.f 

Fresh-water mites. Body usually ovoid or spherical and sometimes 
of large size, and often brightly colored; 1 or 2 pairs of eyes present; 

• See "A Zoological Investigation Into the Cause, Transmission, and Source of 
Rocky Mountain Spotted Fever," by C. W. Stiles, BulL No. 20, Hyg. Lab., Treasury 
I department, Washington, 1005. 

t See "Nordamerlkanische Hydrachnlden," by F. Koenlke, Abb. d. natur. Ver. zu 
Bremen, Vol. 13, p. 167, 1895. "Deutscblands Hydrachnlden," by R. Plersig, Blbl. 
Zool. No. 22, 1897 to 1900. "Hydrachnldae und Halacarldae," by B. Plersig und 


mandibles with a terminal claw; pedipalps 5- jointed and usually long, 
the terminal claw being sometimes bent down to form a grasping organ; 
legs usually 5-jointed, with or without swimming hairs, and joined to 
body by prominent oozal plates (Fig. 705, 1) ; a pair of spiracles on the 
dorsal side of the rostrum; genital pore surrounded by a plate and 
usually near the center of the body; numerous minute suckers often on 
each side of the genital pore; eggs laid on plants, stones, etc.; young 
born with 6 legs and usually go through a complex metamorphosis, often 
attaching themselves to aquatic insects : about 70 genera and 500 species, 
most of which live in fresh water, a few being found in brackish water 
or in the sea, and the genus Unionicola being parasitic in mollusks; about 
100 American species; 5 subfamilies. 

Key to the subfamilies of Hydrachnidae : 

Ci Large red mites with 4 eyes close together on a plate. 

&! Eye plate long and narrow 1. Limnoohartnai 

ft, Eye plate short, broad and paired 2. Eyullnae 

Of Eyes not close together on a plate, but far apart. 
&! Pedipalps chelate. 

Ox Mandibles 1- jointed, straight and needle-like 3. Hydbachninak 

e% Mandibles 2-jointed, the terminal joint a curved hook. 4. Hydbyphantinae 
6, Pedipalps not chelate 5. Hygbobatinae 

Subfamily 1. LIMNOCHARINAE. 

Body very soft, variable in form, red in color; eyes 4, near together 
on a long lanceolate plate: 2 genera. 

LnoroOHA&ES Latreille. Body rectangular; legs without swimming 
hairs, but with spines, and in 2 widely separated groups of 2 each: the 
animals do not swim but walk slowly over the mud and plants in the 
water; 2 species. 

L. aquatica (L.) (Fig. 703). Body red, 4 mm. long: on the bottom 
of ponds; cosmopolitan and common; larvae attached to water skaters 
(Hydrometridae ) . 

Subfamily 2. EYLAINAE. 

Body soft, regular in outline, red in color; eyes 4, near together on a 
paired plate: 2 genera. 

Eylaxs Latreille. Body oval, legs long, with swimming hairs, 
rather close together; genital pore between the first 2 pairs: 35 species, 
the larvae of which have been found on mosquitoes; 3 American species, 
which are rapid swimmers. 

H. Lohmann, Das Tierreich, 1001. "A Review of the Genera of the Water Mites." by 
R. II. Wolcott, Trans. Am. Mlc. Soc., Vol. 26, p. 161, 1906. "Die SSsBwasserfaoDa 
Deutschlands, Heft 12, Araueae und Acarina," by F. Koenlke, 1900. 



E. extender (0. F. Muller) (Fig. 704). Body red, 4 mm. long: in 
ponds; cosmopolitan and common. 

Subfamily 3. HYDRACHNINAE. 

Body soft, sometimes with chitinous plates; 4 eyes, 2 on each side 
and sometimes another in the middle; rostrum usually elongate, forming 
a snout, at the end of which is the mouth; mandibles 1- jointed, long and 
needle-like ; pedipalps chelate : 2 genera. 

Htdsaohva 0. F. Miiller. Body oval or round; legs rather short, 
the last 3 pairs with swimming hairs; genital pore between the last 2 

Fig. 703 

Pig. 704 

Pig. 705 


Fig. 703 — Limnochares aquptica (Banks). A, ventral aspect; B, dorsal eye plate. 
704 — ByUtis ewtendens (wolcott). A, ventral aspect: B, dorsal eye plate. Fig. 
Hydrachna geographioa (Wolcott). 1, coxal plates; 2, genital plate. 

pairs of legs; the larvae attach themselves to aquatic insects: about 33 
species, 8 American. 

H. geographica (Mull.) (Fig. 705). Body oval, arched, dark red in 
color with dark spots on the back; length 7 mm.: often common; 


Body soft, sometimes with chitinous plates, and red or brownish in 
color; 1 or 2 eyes on each side and sometimes a median eye; coxal plates 
in 4 groups : the larva leaves the water and is parasitic on aerial insects, 
returning to the water to complete its transformation; 13 genera. 

Key to the genera of Hydryphantinae here described: 

Ox One eye on each side contained in a chitinous capsule, and a median eye. 

bt Swimming hairs on legs 1. Hydbyphantes 

6, No swimming hairs 2. Thyas 

«, Two eyes on each side and no median eye 3. Diplodontus 

L Hydsyphavtxs Koch. Swimming hairs on the last 3 pairs of 
legs; median eye surrounded by a chitinous plate, but no other chitinous 
plates on the dorsal surface: 17 species. 

H. ruber (DeGeer) (Fig. 706). Body 2 mm. long, red in color, often 
tending to be dark: in wood ponds, especially in the springtime. 


2. Thtas Koch. Like the above but with no swimming hairs on the 

legs; body flattened: 7 species, 2 American, the larvae of which Leave 

the water and attach themselves to aerial insects. 

T. stolli Koenike. Body 12 mm. long, oval and red in color ; legs 

with numerous bristles. 

3. Dmosomnm Duges. 

Body oval or round; eyes 2 on 

a side; no median eye; legs with 

swimming hairs; genital plate 

heart-shaped: 3 species. 

D. dMpiduu (0. F. Mailer) 

(Fig. 707). Body 2 mm. long, 

red in color with an indistinct 

™™ ™' T " tot™ doraJ .pot, »d .too 

Fig. 70S — JTyttrypfoMts* ruler (Wolcott). , ... .„ , 

L com plates ; 2, geniuipUte. Fig. 707— covered with papillae ; larva on 

Dtplodentv dapidau (Wolcott). A, ven- • 1 - L 

tral aspect of male; B, pcdlpalp of female, aerial insects: common. 

Subfamily S. HYGBOBA TINAS. 
Body compact, surface smooth or with fine parallel lines, sometimes 
with ehitinous plates; eyes of the 2 sides distant from each other, either 
1 or 2 eyes being on a side and never in a capsule; no median eye; 
pedipalp not chelate, or rarely so; eozal plates large, sometimes cover- 
ing the whole ventral surface; the larva (except in Unionicola) attach